to me fans are categorized in levels. you see, when i say....

Not a Fan = someone who play a game, but not enjoy it much, or enjoy it a bit

a fan = Someone who play a game and enjoy it a lot

a Big fan = someone who play the whole series and love it.

a HUGE fan = someone who notice all the little details in every game and also recognize all the easter eggs and references.

a fanboy = a douchebag 

Every single member

A wild fanboy has appeared!

:P

*goes and cries in a corner*

*mutters about being called a  douchebag*

I'd say-

Hater: Dislikes a game without even playing it. Forms a (often times inaccurate) opinion based on hearsay. If it's not on his console of choice, it automatically sucks....until it gets ported (ie: Mass Effect/Joe Danger). Then, it's awesome! 

A mutation of a hater is The Hater Elite:  This guy actually enjoys a game quite a bit.  He'll sing its praises and convince people that it's awesome.  Then, that faithful day arrives where people actually begin to like the same thing as The Hater Elite.  This causes T.H.E. to perform a complete 180.  Suddenly, the series that he championed has become shit!  You like Call of Duty?  Too bad it sucks now.  The only TRUE call of Duty is Call of Duty:  The Big Red One.....unless you've played it.  Then it sucks, too.

Game Fan: likes a game and has fun. Would enjoy the sequel. He probably plays Grand Theft Auto, Madden, Halo, Call of Duty, or a combination of the four. He doesn't finish a game, though.  Buys other games in the series when they go on sale.  May not know all of the facts but he/she knows what he likes.  His natural predator is the Hater Elite and the Fanboy.  They will pwn the Game Fan with their infinite knowledge at any given opportunity.

Big fan: Really likes a game. Honestly has fun and would buy the game's sequel on day 1. Maybe even pre-orders.  They will play a game to completion.  They go for the Achievements/Trophies and may even read a comic based on their favorite video game.

Super Fan/Fanatic: Will actually fight you via the internet if you can't remember the name of that one character that gave you the +1 Sword of Blazes on chapter 2 of the DLC. They make their own fan fiction and will actually debate you on whether a Mario game is a real Mario game or a spin-off. They can be quite scary.  Super Fans will play every entry of their favorite game without question. 

Fanboy (Douche): Their love is blind. No matter how good, bad, or broken a game is, if it's from their favorite publisher or it's console exclusive, it is mana from heaven. They don't even like baseball but if MLB Strike-Out 2012 is on their console and not yours, it's game of the year material! They'll take evey opportunity to remind you how much fun they're having and that you couldn't possibly be enjoying your game as much as they're enjoying their game.  They will compare the Metacritic score of a racing game to an FPS if it will suit their agenda.  Graphics comparisons, list wars, sales, and frames per second are the tools of their trade.  They will list 50 games that are available on their console and not yours......but they only own three exclusive games.  Strange creature, that Fanboy.  Strange creature.

d21lewis: All around awesome.

I second this...

You could call me a HUGE fan of Zelda. I won't stop any Zelda game until I have all heart pieces, opened ALL chests, made every single dungeon, did all sidequests.
Coincidentally, I also play LoZ: Wind Waker at the moment, and I'm extremely looking forwad to Skyward Sword.

oh, and I've played through every single Zelda game, btw.

I feel like I'm the first person who gave a serious answer to your post, lol.