Not much on the opponent, I had played every pot and been pretty aggressive.

Full Tilt Poker Game #1090317420: $5 + $0.25 Heads Up Sit & Go (7406677), Table 1 - 15/30 - No Limit Hold'em - 14:03:05 ET - 2006/10/11
Seat 1: Rocketpoker828 (1,945)
Seat 2: Villain (1,055)
*** HOLE CARDS ***
Dealt to Rocketpoker828 [7c 8s]
Villain calls 15
Rocketpoker828 checks
*** FLOP *** [5s 7h 4d]
Rocketpoker828 checks
Villain bets 60
Rocketpoker828 calls 60
*** TURN *** [5s 7h 4d] [Jc]
Villain bets 150
Rocketpoker828 calls 150
*** RIVER *** [5s 7h 4d Jc] [Ac]
Rocketpoker828 checks
Villain bets 815, and is all in
Rocketpoker828...?

Why in the world wouldn't you raise TP + SD on the flop HU? Did you want to let him catch his two pair or Jack or Ace for nearly free?

Either lead out on the flop for a pot-sized bet, or C/R it for a pot-sized bet.

Raise the turn, it's unlikely he called your raise (had you raised) on the flop with just a jack, unless it was J6.

As played, fold the river. No question.

The worst thing to ever be doing with no information and a marginal holding is to sit in call mode. You need to find information, you have to raise on the flop, or on the turn.

You are just on a guessing island on the river.

So, if you've been playing aggressively, why did you decide to not be aggressive here?

Do you only play aggressive when you DON'T hit the flop?

Why did you check/call the turn?

If you thought you were still ahead, you should have raised.

If you thought you had odds to look for a 6 or 7, you were wrong.

Did you actually want to hit your two pair?

As played, let him have it.