Buy, rent or avoid

Ok guys I need some help. Basically because I'm a student and I bought my download festival ticket I currently don't have much money spare and so I would like some help deciding what to get. I am going to be trading a load of games in (around 10) but because they are all fairly old and/or unpopular I'm only expecting to get around enough to get one new game. So if you would be so kind as to give me your opinions on the following list as to wether I should buy, rent or avoid.
 
 Remember I can only buy one, and probably rent 2-3 for a week each or keep one for 3 weeks etc. And I only have a 360 and a average laptop (which can play Dragon Age). Also I currently can't get online with games but that will change in July.
 
Mass Effect 2 - Played the first one a while back and loved it (obviously), however I'm getting a bit RPG'd out. 
Dantes Inferno - I really like games with some mythology, and I've never had the chance to play God of War. Yet this style of game has a real pull on me. 
FFXIII - FFX is probably one of my favourite games of all time absolutly loved the story, however I don't like FFXII and I think it's down to the non-turnbased type combat system.
BC2 - Greatly enjoyed the first one replaying it a few times, and I have no doubt I will love the multiplayer. But wont be able to get online until July at which point I might be able to get it cheaper
Bayonetta - This game greatly intrigues me and I would love to have a go on it currently leaning towards rent this one. Currently £25
Army of Two: 40th day - Was thinking about getting this when it came out, really like the gun customisation. Currently £25
The Saboteur - Seems like a fun, but broken(ish) game. Currently £25
SSFIV - Been really getting into SFIV recently and can't wait to get online in july (presumably most people would have this by then). Currently on pre-order for £25 but will probably have enough money to get it when it comes out.
 
And obviously I could push to get two of the £25 games.

FFXIII - Buy
BC2 - Avoid (Until July)
Bayonetta - Rent
Army of Two: 40th day - Avoid
The Saboteur - Avoid
SSFIV - Avoid (Until July)

 Mass Effect 2 - they took alot of the rpg out so its more of a third person shooter. i love it. played through 3 times.  
Dantes Inferno - the game isnt awful, but it isnt that great. monotonous and kinda boring. play god of war when you get a chance.
FFXIII - this looks awesome. i dont like jrpg's and im gonna get it.
BC2 - id say get this one. the beta is awesome and the full game is going to dominate
Bayonetta - i have no idea what this game is about not do i care to. your choice
Army of Two: 40th day - i rented and beat it. its not as good as the first imo but if you like the whole bromance thing rent it
The Saboteur - id say rent it but after other games. this one wasnt that great.
SSFIV - if you like fighting games get this one   
 
my opinions so you can use them to decide how to go about gaming

whatever you do, PLAY BAYONETTA. it's amazing, even though i am stuck with the lame PS3 version. 

 Mass Effect 2 - Buy
Dantes Inferno - Rent
FFXIII - Buy(to big to rent but maybe try it out in a rental)
BC2 - Buy in July
Bayonetta - Buy but I'd only rent it to be honest.
Army of Two: 40th day - Rent/Avoid
The Saboteur - Rent or Buy cheaply later on.
SSFIV - Buy in July
 
 I recommend: Mass Effect 2.

buy super street fighter 4, rent the rest

I'd say buy BC2 because it'll be a multilayer game that you can keep going to. 
I wouldn't touch Army of Two: 40th day unless you have a friend willing to play through it with you. 
If you're RPG'd out then I wouldn't touch FFXIII or ME2 until later on. 
Dante's Inferno is great and seeing as you haven't played God of War then it's more probable that you'll love it even more. Definitely a game I'd rent for a week.  
I got bored of the Saboteur after a few hours so it's a game I'd only recommend touching if you've got absolutely nothing else of high quality to play.
Personally, I hated Bayonetta. Not because it's a bad game or it's made wrong because the gameplay itself is fine. I just couldn't grasp the whole over-the-topness of the game. Try it out and see if you like it.
As for SSFIV I'm not really a fan of fighting games in general so I can't really give any useful information concerning it.

Thanks guys, think I'm going to;
 
Buy - Mass Effect 2
Rent - Dantes Inferno, Bayonetta
 
And end up buying BC2, FFXIII and SSFIV later on.

Renting Bayonetta is a sin. If anything rent The Saboteur.

ME2: Buy! one of the best games in a long time
Dante's Inferno: avoid... ugh...
Super Street Fighter: Rent, and if you can handle it, buy...
FFXIII: Rent, Final fantasy games are hardly worth second play throughs

BUY ME2
Dante's Inferno... we'll see. Rent maybe?
BC2 - if you have time, buy. no time, rent
Army of 2 - rent if you're really feeling it
Bayonetta - again rent, then buy if you like
SSF4 - Buy if you dont have SS4
Saboteur - rent
FF13 - buy

multiplayer in bad company 2 could keep you occupied for endless hours.

I wish I could be more help, but I haven't played any of the games myself yet. Still, I always recommend that people rent games before buying them if they can. If you have a GameFly subscription or something like that, I think it's good to take advantage of it. It sucks buying a game that ends up being a disappointment. Especially when they cost so much money. Not to mention the fact that they all drop in price so quickly these days anyway.

I'd say buy BC2, I don't really care too much about any of the others. 
 
Maybe FF13.

Buy them all! Buy them all new and not used! Murder someone for their wallet if you have to.

"Mass Effect 2 - Buy
Dantes Inferno - Rent 
FFXIII - Rent
BC2 - Rent but only because you can buy one of them.
Bayonetta - As above.
Army of Two: 40th day - Avoid but rent if you must.
The Saboteur - Rent
SSFIV - Buy later if you can manage it."

Avoid the Saboteur thats for sure.
 
Buy Mass Effect 2 and BC2. 
 
The rest i can't really comment on, as i have only played these and the demo of BC2.

oh god, really? 2 fucking pages of this. unstick.

Buy Bayonetta. It's easily the generation's best 3D beat 'em up, and with the idiosyncratic difficulty levels (Hard has repositioned enemies and Very Hard takes away one of your most useful abilities, so both of those are quite different from Normal), the optional challenges (there are tons of hidden Alfheim Portals with special challenges, a very hard secret boss that takes quite a while to unlock, and the Lost Chapter, a ridiculously difficult arena challenge) and the ranking (getting Gold or Platinum on all chapters takes a lot of time and skill even on Normal), you can play it for 100+ hours. 

Rent... whatever. Just buy Bayonetta.