This was at a live game. .5/1 nl, 5-handed. Villain is aggressive and a good player, he plays just about any hand preflop, and somehow tends to win. He's that good postflop. Table is ultra aggressive. I have everyone covered, with about $250. everyone else has about $100.

Hero is UTG+1 (cutoff) with 9[img]/images/graemlins/club.gif[/img] 8[img]/images/graemlins/club.gif[/img]
Folds to hero.
Hero raises to $4, only big blind calls.

Flop is 5[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/club.gif[/img] J[img]/images/graemlins/heart.gif[/img] (Pot $8.50)
Villain bets $5, Hero reraises to $15, Villain thinks and calls.

Turn 5[img]/images/graemlins/diamond.gif[/img] (Pot $38.50)
Villain checks, Hero checks.

River T[img]/images/graemlins/club.gif[/img]
Villain bets $20, Hero ?

I am not sure what to do here. He's bet half the pot when I hit my draw. If I call his bet, I am probably missing a lot of value from straights and 2 pairs. However, if I reraise and he shoves, it'll be tough to tell wether he has me beat. Keep in mind villain and I have been in a lot of pots together with a lot of action (for example, I called his pot-sized bet on the river a few hands ago with bottom pair and won).

Edit: If I raise and he puts me on a flush, I wouldn't put it past him to shove knowing I know he knows that's most likely what I have.
Also, villain's stack was more like 150. He has plenty to push me around with.