Sonic X

They are both based around a video game series. They are also funny, and aimed at a somewhat younger audience. 

Both of them are based off of a video game and they are both about a boy who learns more about his animal type friends and they both have alot of action in them. 

They both are basically based of the same idea: different worlds being parallel to earth. They also have fun talking animal-type things. 

They both have a lot of the same elements in terms of fighting. This is another one of those epic animes that is great for all ages.  

both being based on notable video game series as well as edgy characters as well too and also lots of stylish action in it as well. 

Characters are similar, with similar dynamics: Natsu is an optimistic, adventurous, happy-go-lucky guy, like Sonic. He has a companion without whom he doesn't go anywhere, Happy, which is similar to how Sonic behaves with Tails. Lucy drops into the story very suddenly, but later becomes an integral part of the team, wants to stay with its members for as long as possible, and takes a liking to the adventurous main character, as does Chris Thorndyke. Grey's a hot-headed, kinda aggressive person, who has constant conflicts with the main character, like Knuckles. All characters have special abilities. They have a similar tone as well (mixing drama with comedy regularly, with several action scenes). The main difference is the setting. read more 

Sonic X and Hikari no Megami are both based on popular video games. Sonic X is based on the Sonic adventure games and Hikari no Megami are based on Kid Icarus, The legend of Zelda, and super smash bros. Sonic X may be a longer anime then Hikari no Megami but it is still really good for a short 2 minutes. Watch Hikari no Megami if you like Sonic X. 

Wikipedia states that both Legend of the Galactic Heroes and Sonic X are space operas. So yeah, they are the same, I guess 

Both involve characters from other worlds coming into ours with distinguished human and alien casts. They also both have major early 2000s energy 

Superpowered anthropomorphic animals collect magical stones to save the world. 

These two anime are closest to each other and character. Sonic like Joker Miles like Hachi Knuckles like Spade Amy like Queen They also have science, comedy, adventure and shounen. They also can watch by children 

-Both have spikey hair that can go up and turn gold. -Has a rival anti-hero who changes in the later episodes. -Both have 7 items that power up the user and the other wish for stuff. -Has a best friend Tails/Krillin since the Og days such as Classic Sonic era and Og Dragon ball.  

Kind of similar with the story between shadow and ryuko in terms of how they were created and such. Also this is shadows favourite anime! how could I not put a recommendation!  

- Powerful characters - Fight to live - Want freedom into their own hands  

Both anime are SEGA series about a group of friends going on different adventures and is mostly episodic, especially for their first halves. They also take place in the same universe, as Sonic becomes an important character for an episode or two in SeHa Girls/SEGA Hard Girls. 

both have anthropomorphic characters.each charater has some type of ability or strength that will be sure to knock out their opponent. 

High speed adventures with main characters who looks very similar in both appearance and mindset. The main villains are genius scentist creating robots and mechas, especially against the heroes. Similar situations and events with funny fights. 

I think both is similar for the main persons come from a other world and do every thing to come home again and it is very mutch of demolish  

Both involve a well known Videogame hero traversing into the human world, learning about how society works on top of fighting the videogame villain using THAT device every episode. For Goemon, it's Ohagi and Impact. For Sonic, it's the power ring. Either way, both are enjoyable, but both also involve the hero sharing the protagonist role with the token 'Boy human' character, whether it's Goemon's 'Tsukasa', or Sonic's 'Chris Thorndyke'. Both also end with climactic space battles in one way or another, but I'll leave that or you to watch and enjoy. :) 

Both are based on video games that have a mix between action and humor. While Sonic X is made for all ages, Neptune: The Animation is made for a more mature audience. 

Both shounen and action, somethimes funny 

Both of these action adventures have a blue-haired main character with a previous mainstream association (Both Disney's Aladdin and Magi's Aladdin were adapted from a book, while Sonic from Sonic X is everyone's favorite speedy video game character.) 

The main characters in both action shows consist of anthropomorphic animals who fight evil monsters, but Eto Ranger's characters all wear clothes instead of just accessories. 

Whilst watching Star Fox Zero: The Battle Begins, I was heavily reminded of Sonic X. Sonic and Star Fox are both based on popular video game series with human-like animals saving the day. If you liked one, I'd recommend the other.