Quick line check .. usually fold this river, right?

[poincaraux]

I posted this in the middle of another long post today, but it's pretty burried:

I raise PF and get 1-2 callers. I hit something like top pair, good kicker, but there are two suited cards on the flop. Turn is a blank, bet, call. River makes the flush. I bet the river for 1/3-1/2 the pot and get min-raised.

I've been calling most of these, and it seems like it's always the flush. Is it always the flush? Can I comfortably fold here, or is it really read-dependant/you need more details about the particular hands?