Dragon Crisis!

Both of these shows are about artifacts. Dragon Crisis! has them in a more positive light, while C³ has them in a darker light. But some of the objects actually have a life of their own. 

Like many have pointed out, a semi-inept boy brought into fighting a great bad organization via a Tsundere girl with fire powers (both played by Rie Kugimiya). Additionally, Yoshida (SnS) is very similar to Misaki Etō (DC). A shy girl in the boy's class who has some level of attraction she can't seem to get across. *IMHO, Shana is the better of the two series... watch it. Especially if you like the character of Rose.  

Similarities: Both lead female characters have what you called a "LOVE AT FIRST SIGHT" with the male lead characters. Both male leads pledge to protect the female lead. Both have school, harem, magic and supernatural genres. Both have childhood friends whom were placed on the sidelines. Both male leads have special abilities. Both lead characters together with their female partners were compelled to join in a secret organization. Both were a pseudo harem. Dissimilarities: The female lead in the other anime is a dragon while in the other one is a vampire. The secret organization the characters were in, differ, because one organization is more on scientific and functions like a club, while in the other one, the organization is a "TOP Secret" one where it's authority goes way beyond the government's control. The childhood friend in one anime is shy, clumsy and doesn't do anything, in the other, the childhood friend there is not to be trifle with......not just yet, maybe, when she reaches her boiling point, in fact she may have some kind of sinister going. When it comes to the male lead's special ability, one was endowed with it when he met the female lead as a child, while the other one has his special ability with the knife (or dagger) that he welds. One has mystery as it's extra genre, whiled the other has ecchi and vampire as it's extra genre. The male lead in DC has his cousin and some of his harem as his side kick while in ITKU the male lead was drafted to be a reluctant slave by the student council president who welds great power and influence.  read more 

In both series, the MC gets stuck with a dragon in the form of a girl. 

Many similarities with Dragon Crisis except that it's a more older version , both involve dragons, the main character is attached to his dragon which is a girl. Also the dragon girl saves him when they first met. 

Both animal have several cute dragon girls (and a black male dragon) learning how to interact with humans. Both are cute, both have lolis without being gross about it, both are well-animated, and both are funny (although Dragon Crisis can be a bit more serious). 

Both series have a male character who "finds" the female character. The girls cannot speak much initially (aside from names) or have much knowledge, but they learn more and more as time goes on. They both also have romance in them.  

Both anime has weak male main who finds a powerfull girl. and those both girls too powerfull but they dont know yet. 

Both have similar settings where the trading, hunting or stealing of treasures is the main plot of the story Both protagonists have mysterious and strange back stories The female MCs are blonde lolis  

Both female leads are of different species, aggressive toward the main protagonist (Kanokon is more ecchi), and have a strong fiance. Both main characters need to sync to gain power. 

They both are in the fantasy/action/romance genre, Zero no Tsukaima will not disappoint you. 

Both guys in these anime was save by the female protagonist in their first meeting. Both are harem, romance, comedy, and action. Both anime are definitely worth watching! You'll definitely enjoy every single episode of it. The difference between these two anime is that the girl in Dragon Crisis is a Dragon while the girl in Seto no Hanayome is a Mermaid! 

Both main guys have to take care of a girl. Both female protagonists are very attach to the male protagonist. The difference between these two anime is that the girl in Dragon Crisis is a Dragon while the girl in Tasogare Otome x Amnesia is a ghost! Both anime are definitely worth watching! 

-Both show involve a main protagonist with some sort of magical power. -There's some ecchi for those who like it. -The stories aren't fantastic, but they are fun to watch. -The females of these series are anthropomorphic people with animal characteristics. (more than one/series) -Romance is something that exists in both of them. 

The main character is forced to care for a girl who is completely in capable of taking care of herself. The female protagonists are also in love with the main character, except in Dragon Crisis the love is more direct rather than in Sakurasou 

The main characters in both of these anime are living normal peaceful lives until the appearance of a 'Different' kind of person in Dragon Crisis its a dragon named 'Rose' and Haiyore! its a deity called 'Nyaruko'. Upon the appearance of these characters in each of the shows the main characters so called peaceful live is turned upside down and makes every day into an adventure. Towards the beginning main character thinks of them as an annoyance but as the story progresses they start to warm up to each of them and form a strong bond even risking their safety to rescue them at times. Both Dragon and Haiyore! have a good element of comedy as well as abit of romance and are both enjoyable to watch. read more 

Similarities: very young supernatural girl being targeted by powerful enemies, has action scenes, and a similar type of romance.  

Both anime contains.. -- Both somebody knew from the past, but the main character could not recall them int heir memory at all. -- Both main character tries to get rid of them in their lives, but failed. -- Both main character, the person they are trying to get rid of contains magical powers, great looking, and loyal to the main character like a dog. -- Both contains action somewhat + very good + romance + comedy, kinda. 

Both main guy has to take care of a girl. The difference between these two anime is that the girl in Dragon Crisis is a Dragon! while the girl in Sankarea is a ZOMBIE! Both anime is definitely worth watching and both anime deserve a second season! 

Both have male/human protagonists with a female 'friend's (Dragon in Dragon Crisis!, Edel raid in Elemental Gelade) Both have female 'friend's who are able to powerup the male character Both have a certain word/chant they say before powering-up (pardon the crude word) Differences: Elemental Gelade is where the female friend becomes a weapon, and the world is filled with people who can do that, while (for now) only the male protagonist has the ability in Dragon Crisis. Elemental Gelade uses a unique chant where both the human and female has to say in sync, while (for now) both Ryuji and Rose say 'Engage'  

Both of these shows deal with the fantastical and antiquities that happen to have powers. 

Legends surrounding artifacts and the main character is male. 

Both Anime have fairy tal type stories with modern twists to them. One... Dragon Crisis, takes place in a modern day setting, while Fairy Tail takes place in a time of an older era, but is given modern day trends and a small bit of technollogy, like vehichles that run on magical power and trains. 

Crazy, out there, and upside down. Both of these series exhibit an older style, one not typically seen anymore, but the humor is corny, crazy, and out there. And yes, one is fantasy, one is sci-fi, but that doesn't make them any less out there and wacky. That's about as far as I can go without spoilers. 

I am going to say that if you are interested in dragons and you liked one Anime, you very well may like the other. I can't go into more detail else I'll give spoilers for "Gedo Seniki" for those who haven't seen it yet. 

Again, Rie Kugimiya plays a brilliant Tsundere character in Taiga. Who is paired, remarkably enough, with a male named Ryuji. The title ToraDora comes from Tiger & DRAGON. There is no fighting in ToraDora, it is more of a HS rom-com. One of the best IMHO. But both males are good at the cleaning/cooking. Yui Horie lends her voice to supporting characters in each as well as the song tracks. Well worth watching for any fan of rom-coms or of Rose (Rie Kugimiya). 

Both anime have a male and female duo. The female has some special power and bonds with the male to create a greater power. In both anime the pair need each other to overcome the organizations/individuals that are out to get them. 

well , as the story progresses new characters come up . and well they all fallen for the protagonist and protagonist has a godlike skill xD  

both the male leads want to protect a girl. Both have magic and romance genre. 

Kinda similar awesome art and animation. There are levels(breaker) that we didn't know. There are some cute lolis like Rose and Misaka in To Aru Majutsu No İndex.  

Random but funny plot. A lot of action and ficton, harem and just a bit of drama. 

Both show a harem of girls who are not humans and have super powers. 

Both female leads are loli, don't look adult or mature. In both series, the male leads are protecting the female lead.