Motorstorm is definitely a good buy. (Even though I have used my PS3 3 times since buying it around a month ago)
If you cant find any nice games, I suggest waiting until November. All the "hot" releases of this year will be out by then, maybe a few exceptions.
I went to pre-order Assassin's Creed today (UK ETA November 9th) but the fire alarm in the shopping centre went off so we had to evacuate.

(A sign maybe?)
If you are limited to what you can buy (most people cant buy every game ever released) then I suggest only buying Resistance for now, and save your money for the better games that will be out in a few extra weeks. Resistance is not my cup of tea but it should keep you entertained until the games you do want are released.
If push comes to shove, just play that duck game for hours like I did.
