RockmasteR

hello
NFS Prostreet is totally different from Carbon
Carbon is illegal street racing, at Night with cops and you can race with team mates and the game has its own story and the game has a free roaming mode
Prostreet is legal racing with closed tracks and the game has a limited story about being the Street King, the game happens only at day time, no cops and with a very annoying commentary and speech, the racing is good tho
if you like cops and chases and if you liked Most Wanted you could like Carbon (the only common thing in MW and Carbon are the cops but they are more stupid) of course the customization stays in all NFS including in Prostreet
Prosreet was a bold move from the NFS team to refresh the series a bit but I think they fail a bit in it
so IMHO Carbon is better than ProStreet
but of course it's up to you
if you like closed tracks and legal races go for GRID but no customization but the game is amazing
or maybe you can wait for the new NFS Shift coming in Fall 2009 it'll be big