Should i buy Elite Beat Agents or Theme Park DS ?

Hey guy, just a quick question. I can't decide which of these 2 games to pick up, they both look brilliant but i currently only have enough cash for one.

Now i wouldn't mind picking up Theme Park DS since i used to love this game years back when it came out on the PC and to be honest i want to buy just for nostalgia (and also because it's portable now!) but i might find it's not quite as good as i remember it ! Elite Beat Agents looks really great and different and i really love games such as Guitar Hero and this looks like a very similar styled game. I can't help but feel this game miiiight get old fast but obviously i've never played it so i can't be sure but i definitly want to pick this game up at some point but i'm just not sure which of these 2 i should grab first.

 Any advice guys ?

I have no experience with Theme Park DS so I can't offer an opinion there. I picked up Elite Beat Agents this weekend though and it's pretty good. I beat the easy mode in 3 hours, and that was playing through each mission at least twice. Some of the later missions I had to retry a few times because they were sort of difficult while all the rest I voluntarily went back and played through a second time. The game definitely has a second, harder difficulty setting to play through and I strongly suspect that there's a third, hardest setting but I don't know for sure.

I think there's going to be some mileage for replay value trying to perfect your score on each mission, and in turn, once you get really good you might be able to get some mileage out of just playing a mission and acing it even though you're too good for it to be challenging but are playing it just because it's a fun game to play and really enjoyable when you're doing well. If that makes sense.

The game also has a multi-player mode but I didn't really read that section of the instruction book yet and I haven't played it so I don't know if it's any good. Overall I think it's a pretty good buy, but I think there's a definite chance that the game could get boring really quick.