I play microstakes, and recently have noticed there are a few players who will have VPIP of 35-50 and a 3B of ~20. So they are really just trying to apply a lot of pressure IP with a lot of hands. I'm not limping, hardly ever limping really, but always seem to be playing oop. Other than not playing tables when they are on my left (sound advice that I am paying more attention to), what might be some other strategy?

Yes i would like to hear some advices here as well. Sometimes i go heads up with maniacs and have nothing on a flop but some A high, but i proceed to check call his agression and win some pots with just A high. Kind of think its not a correct play, but hey i got A high, and he c-bets al the time. Maybe is beter to reraise in such position right away?

I also play all hands sometimes. It happens that the card goes and manages to break everyone in a row. And sometimes I don't get the right card and lose a lot. Then I sit and choose a card to play with. If you don't want to, don't play with them.

You should not be limping, if ever. If you are first in, you should be raising. If you are oop from the maniac, tighten your raising range and start 4-betting more or widen your calling range if the maniac three bets you. Call down to the river. (If you call turn then fold on the river, you are doing exactly what the maniac wants.)

There are videos out there that should help. Here's a couple:

You Tube

You Tube