I have sold my ps3 for a 360, NEED LOTS OF ADVICE!!!

[ps3-sales!]

So i just formatted and sold my 250gb (originally 20 gb) ps3 for this xbox 360.

I got that 360 so I could afford a lot of games/xbox live/accessories ect.

This is where vgchartz comes in. Being fairly new to the non-huge 360 games, I don't know it's entire library, so i need a lot of help of a bunch of good games to buy. 

So if you wouldn't mind to list some games and give like a reason why you think its a good/great game, that would be GREAT.

So far I'm getting halo 3, gears 1 2, left 4 dead 1 2, and modern warfare 2. 
I don't just like shooters though, I like action, adventure, RPG's, and some JRPG's. 

Also what are some must have accessories i should get besides xbox live? I don't need the wireless thing, way too expensive plus ethernet wired is fast for me. 

Thanks a ton in advance!!!

EDIT: I might want to change my sig now hahahahaha