Here's a hand I played yesterday. The place I play at has two regular maniacs who frustrate the shit out of me. They VPIP nearly 100%, regardless of preflop action. They both bet big constantly to put on max pressure. This particular guy always opens big, if you open he will often 3-bet 5x or more, stuff like that. Here's the hand with my thoughts:
$1-$2, 8 handed with plexiglass. Effective stack approximately $710
UTG limps, I open to $15 with 7c7s (this is standard opening size, especially from early position. Pocket 7s is the lowest pair I'd open with).
CO calls (man calls a lot preflop only to fold to almost every c-bet). Maniac calls in SB.
FLOP ($47) 9h2h2c. SB leads for $35. I put him either on a 9 or a heart draw. He'd lead either. If I raise to $100, he'd most likely 3-bet the 9 and just call the heart draw. I feel my 7s need protection here. CO folds. SB calls.
TURN ($247) Ad. SB checks. I bet $125. There is no way he has an ace. He would have 3-bet preflop. He bets/raises every ace pre no matter the action and will call his stack off pre with any ace. He calls.
RIVER ($497) 4c. He jams for $535. ???????
I have him on a missed flush draw or a 9 at this point. Nothing else really makes sense, though for that size bet, he's super polar and now I have third pair.
I ended up tank folding though I feel I should've called. He turned over a missed flush draw to try and tilt me.

The other maniac is a little different. He opens almost 100%, and I'm not exaggerating. Though his opening raise size is smaller. If someone opens he calls 100% whether in position or in the blinds. He calls 100% of flop c-bets unless someone jams and he has nothing, etc. What he does is check-raises big every single time someone double barrels a turn. He will do it with air, bottom pair, etc. Very frustrating.