Which game should I get (details below)?

Both really.They are both great games. 
And oh yeah,welcome to Giant Bomb.

I like open world action games a lot. I want something that will last me a long time and is really fun. I recently beat Assassin's Creed 1 and really enjoyed it. I also recently played Just Cause 2 at a friend's house and enjoyed that as well. I'm intrigued by the AC story, but ACII doesn't look like it will last as long as JC2 (a friend of mine beat it twice in a weekend). On the other hand JC2's story is awful and the shooting is bad. Which should I get?

I agree with Fire Prince, both games are awesome in their own ways.

I didn't like Just Cause 2, so I'd say go for only AC2. 
But if you got some extra cash and really want to buy two games, I definitely recommend Singularity. 
 
Welcome to Giant Bomb. ;)

JC2 is fun and all but so utterly repetitive. It only has a lot to do, because you can do the same thing multiple times. Add on top of that the terrible voice acting, repetitive missions and a story you cant care about, you are better off going with AC2. The gameplay is improved plus the story gets more interesting. Either get AC2 or look for another game.

Both games are good in their own ways
Although if you HAD to choose one I would go with Assassin's Creed 2
Much more polished than Just Cause 2, and Just Cause can get a little repetitive, although it's stupid fun

"JC2 is fun and all but so utterly repetitive. It only has a lot to do, because you can do the same thing multiple times. Add on top of that the terrible voice acting, repetitive missions and a story you cant care about, you are better off going with AC2. The gameplay is improved plus the story gets more interesting. Either get AC2 or look for another game. "

AC2's story gets kind of loopy, but it's pretty great. Haven't played JC2 yet, though.

If you liked the first Assassin's Creed, you're going to LOVE the second one.

" @arab_prince said:

"JC2 is fun and all but so utterly repetitive. It only has a lot to do, because you can do the same thing multiple times. Add on top of that the terrible voice acting, repetitive missions and a story you cant care about, you are better off going with AC2. The gameplay is improved plus the story gets more interesting. Either get AC2 or look for another game. "

 Second that about JC2.That voice acting is soo bad that it is beyond awesome. THE REAPARZZZZZZZZZZZZZZZZZZZZZZZZZZZ. "

Just Cause 2 gets repetitive, despite the cool tricks you can do. AC2 on the other hand, I haven't played yet.

Haven't played either but....hell if both's an option, go for it.

just play WoW or Team Fortress 2 those games aren't that great

Well, it looks like I'll get both! Thanks for all the help.

" just play WoW or Team Fortress 2 those games aren't that great "

I just bought Assassins Creed II yesterday for 20 bucks. I really liked the first one, but haven't fired up the second. I also bought Dead Space for 10 dollars, which I think I'm going to play first. This summer is a great time to brush up on missed titles!

I'd say Assassin's Creed II. Both games have about the same level of gameplay (actually, Just Cause is probably a little worse). Overall I think Assassin's Creed II is the better title.