Villain was loose

Party Poker 0.50/1 Hold'em (6 max, 5 handed)

Preflop: Hero is Button with , .
UTG calls, MP calls, Hero raises, SB calls, 1 fold, UTG calls, MP calls.

Flop: (9 SB) , , (4 players)
SB checks, UTG checks, MP checks, Hero bets, SB raises, UTG folds, MP folds, Hero calls.

Turn: (6.50 BB) (2 players)
SB checks, Hero bets, SB calls.

River: (8.50 BB) (2 players)
SB checks, Hero bets, SB raises, Hero calls.

Final Pot: 12.50 BB

His c/r on the river was very awkward. He's trying to convince me he has KJ, I think. The pot was a decent size and I had some doubts in mind he had KJ, so I called. I only have to be right 10% of the time and so far calling down with TPGK here has been profitable.

Like I said in some of my other posts, against unknowns I generally call down river raises and check-raises with decent hands. I remember TW mentioning calling these raises to be leaks. Maybe at higher limits this would be a bigger problem, but at .5/1 and 1/2 I find people bluffing here at least 10% of the time.

(He turned over J7o)

Another example... raised on the river with TPGK again:

Party Poker 0.50/1 Hold'em (6 max, 6 handed)

Preflop: Hero is SB with , .
UTG calls, MP calls, 1 fold, Button calls, Hero raises, BB calls, UTG calls, MP calls, Button calls.

Flop: (10 SB) , , (5 players)
Hero bets, BB calls, UTG calls, MP folds, Button calls.

Turn: (7 BB) (4 players)
Hero bets, BB calls, UTG calls, Button calls.

River: (11 BB) (4 players)
Hero bets, BB folds, UTG raises, Button folds, Hero calls.

Final Pot: 15 BB

Results in white below:
Hero has Qs Ac (one pair, aces).
UTG has Jh Kh (one pair, kings).
Outcome: Hero wins 15 BB.

That time his raise just didn't make sense.

Party Poker 0.50/1 Hold'em (6 max, 6 handed)

Preflop: Hero is SB with , .
2 folds, CO calls, 1 fold, Hero completes, BB checks.

Flop: (3 SB) , , (3 players)
Hero bets, BB folds, CO calls.

Turn: (2.50 BB) (2 players)
Hero bets, CO calls.

River: (4.50 BB) (2 players)
Hero bets, CO raises, Hero calls.

Final Pot: 8.50 BB

Results in white below:
Hero has Jc Tc (one pair, tens).
CO has Th 9s (one pair, tens).
Outcome: Hero wins 8.50 BB.

A few hands before this, I caught this villain bluff-raising a river scare card. Here I don't know what he was trying to represent. QT? I called not only because he's been caught bluff-raising the river often, but also because I had a decent hand, it was likely he also was on a draw, and because his river-raise seemed sketchy.