Inukami!

Both are extremly funny anime. Mainly focusing on the comedy and less on the romance aspect. Both have a perverted and loveable main characters.  

Others have recommended animes like Chobits or DearS. While these animes are similar in story, they don't have the same feel as Sora no Otoshimono. The humor of Sora no Otoshimono has the exact same tone as Inukami. Extremely ridiculous, over the top, ecchi humor that is presented in a unique way. This is interspersed within more serious arcs that provide the occasional relief from the outrageous comedy. Basically, if you laughed your ass off watching Inukami, you will find yourself doing the same for Sora no Otoshimono. 

Both animes have a certain panache with humour that is SO wrong but insanely funny at the same time. There aren't many shows that can make me hurt cos I laughed so much. 

Inukami also has a diety involved in the main plot, and the ecchi aspect is off the scale. Has a generous ammount of comedy along with an enjoyable story, its a series that gives you the feeling should i be watching this, or awww...kawaii 

Both are typical harems. Bunch of girls like one guy, who just happens to be freaked out by having so many girls like him. Usually can't keep any of them happy for any length of time either. 

I can't believe no one has pointed this out already... The following could describe either one of these shows: A young mans lecherous behavior ends up getting him bound to a beautiful green haired girl who he quickly loses interest in since she punishes him everytime he looks at another woman. In both cases the girls are supernatural (one is an alien, the other a dog spirit) and along with the male lead they end up encountering lots of spirits and other unusual things. 

the story style the main charecters Yoko and Kuugen are just too similar 

These shows are similar in that they both are about a spirit befriending a young guy, and there adventure together trying to stop an evil/unleashed force. The only difference I have seen so far is the main male protagonist in this series is far less lewd and is more trying to help then get his own "harem" 

The MC are identical becouse they are both pervs and they both have good female characters around them. 

there both insane  

Almost the same kind of art, same kind of humor (a bit ecchi :3) and the same kind of characters. There is also that master and familiar thingy. 

Both of the anime is tell about pervert boy that do pervert thing or try to do something pervert. Both of them Ecchi and Romance and really funny anime . two of this anime show us a kind love, funny love. if you like Inukami !then you might like Tonagura! this two really funny anime. sry about the mistake in spelling. 

Both has a group of people with spiritual powers trying to protect the peace. 

One boy always been beat by the main girl who loves and doesn't love him at the same time. Sometimes surrounded by many girls like in Love Hina and as always leading the main to be beaten. Also Youko (Main Inukami!) and Naru (Main Love Hina) does not only share the same Seiyuu (Yui Horie) but also the same violent and love & love not attitude.  

it also somewhat random and has a love story but this show has some ecchi parts but it is very funny. 

sick characters with two main guys/ girl 

both of these series is simmilar because of their characters. inukami got a main character (boy) who is very ecchi and always tries to flirt with girls all around him Green Green has a main character and some supporting characters (girl) which is just as ecchi as the main character from inukami 

Both shows fox goddess helping the MC 

Very similar dynamic between protagonists (Lum x Ataru, Youko x Keita). Also, both heroines have mystical powers and green hair. 

Although these two shows have many differences, the main characters and their character development make them similar. Yato and Keita have both flaws and initially are not taken seriously and not treated with respect by their peers, but they both have an interesting background and redeeming qualities that make them likeable, and those at the end also earn the trust and respect of others. Also the two shows are both about minor gods and supernatural powers. But beware of the different genre: Noragami is an action shounen anime, while Inukami! is a comedy with much perverseness and some ecchiness, so perhaps one or the other is not suited to you depending on your preferences. read more 

Main characters original love interest is sidelined by a more forward female character  

A god/spirit type girl person who subverts expectations and becomes master of a human, actually loves the main character and doesn't mind being seen naked? There you go, pick whichever show you want. Though Inukami is more on the funny side, and is mostly comedic filler, Tsugumomo actually progresses story at a reasonable pace. 

The show GN is about shungo a martial artist in training who has to take care of Mayu a succubus. she has androphobia and is scared of most men besides shungo. he was given the task of taking care of her so she gets over her fear. it is like inukami because the main characters live with each other and fall in love with each other. both series the main characters met when they were younger. 

Both are fox yokai helping the MC with life problems 

Instead of the usual bland and generic male protagonists we get super horny ones with a harem of super powered girls. 

Bad day at work? Lonely, and finding life meaningless? Here's the anime for you! Both feature dedicated 'wives' or 'waifus' in slice of life comedic situations with MCs who are more useless than eraser dust. 

The main characters of these animes are so much alike it's amazing. Both share the same amount of pervertedness, same morals, same almost everything. They also have the harem thing going on even though in Inukami it takes a little bit more time to progress. Both anime have that side character loves the main one but the main really doesn't care so they get the shit beat out of them thing going on, which is fun to watch. I highly recommend this if you like Sora No Otoshimono. 

about relations between people and animals with elements of mysticism, besides the main characters similar 

They're both surreal, oddball comedies designed for one purpose - to make you laugh. 

Both shows are comedies with great characters. Although Umisho has a more coherent plot than Inukami, and their stories are about completely different things, they both have one thing in common: They're both extremely funny in some very, very, very, very, very WRONG ways :D If you liked Inukami then you'll definitely like Umisho - and vice versa. 

Busou Renkin and Inukami only masquerade as intense action series but in reality are filled with goofiness and laughs. Both boast antagonists (at least at some point) who are hilarious perverts, both have likable leads, and both have a fair amount of MANservice, to boot. The action and fights aren't bad, but the real value in these series come from all the laughs. 

Both are oddball anarchic, and a little bit ecchi, and both are very funny in some "wrong" ways. 

If you liked the silly harem situations in Inukami, and the way the main character always gets into trouble because of the others, you will definitely like Mahoraba. Though Mahoraba doesn't have ecchi scenes and is more of a romance anime.  

Both use complete crazyness (Is that a word?) to produce a hilarious anime. 

Both series have silly characters, arbitrary romance, and so many silly, disjointed scenes that you can't help but laugh. 

Both male leads have the same name; also they both have a powerful female partner that they have made a contract with. 

Both have story and character similarities. Also the genres are very similar. 

Teams of powered girls with a male "lead" who is constantly heavily mistreated from them. Both have ecchi and gags, with ridicolous and weird but strong enemies. Inukami is more "classical", while Kore wa Zombie Desu ka is more chaotic and splatter. 

well both are ecchi and both have to sorta do with spirits both men are perverted and are surrounded by pretty girls they both are basically alike  

A group of girls with different ages among themselves, involved in gags, ecchi moments and ridicolous enemies. 

both are about wolf and dog people. both have a guy who finds a girl who has powers and must now fight. inukami is alot more funny though. very different characters 

Comedy and characters with tail and ears. 

Both series feature a similar mix of ecchi humor and the occasional action-scene, and they both star a young man who has a girl living in with them. Said girl has superhuman abilities, a troubled past and a very disapproving attitude of those porn-magazine the boy keeps looking at! So if you like either one of these series, there's a good chance the other will appeal to you as wel. 

Both will keep you laughing. They both have harem and ecchi. Both main female characters are voiced by Yui Horie. OP and ED songs are also by Yui Horie. If you like Inukami! then I am sure you should also enjoy Nagasareta Airantou. Not always the other way around though.