and is there an other kind of mining more profitable than scrypt mining for my nvidia cards ?
well yes, scrypt-jane is currently about twice as profitable. It requires a binary built from the current cudaminer github repository.
Expect 3.2-3.5 kHash/s from your GTX 660 Ti. No idea about your GTX 460. Maybe the total is around 5 kHash? Look up on the yac.coinmine.pl stats pages how much BTC per day that yields at current YAC->BTC exchange rates
Christian