Reasonable on 31 July 2009
Try Battlefield demo first is obvious move.
Echochrome is great but is a single player puzzle only, so if you lean to coop it may not be to your tastes.
Personally I'd actually recommend Wipeout HD or Flower, which I believe are the best games on PSN right now (with Battlefield and Warhawk close behind) - but of course they may not be to your tastes.
A fair few PSN titles have demos, so I'd grab as many as you can as that may help you.
I guess if you want to think laterally you could stick to Battlefield demo right now as in the end you are playing the game for free and online vs opponents at that, and pick something else then upgrade Battlefield later if you like it enough.
Try to be reasonable... its easier than you think...
