my fav character is sindel, and i guess my fav stage would be the sky temple.

Fav. Puzzle Fighter would be Sindel with her Arrange and when I get tired of her hair getting in the way I'll pick Jade with her Stack.
My favorite stage would have to be the Dead Pool, loved MK2 and this stage especially since they even had the original music and the "Aww Waa" sound when someone was knocked into the acid.

Raiden, his storm is the perfect way to finish someone off in puzzle, and Id say ying yang beach as my favorite puzzle arena.

Mines sub. freeze is very effective if used at the right time.
Stage is ying yang island

ying yang island... and my fave is Kabal. with his double bomb. I think it's very effective. Starts off as a denfensive move, then goes to an offensive. Think of it this way... your blocks are near the top, get the double bomb... 2 of the4 colors r gone, so the other 2 stack and gather at the bottom (sounds like this Sindel's, only a bit better in my opinion). Wait till you get a dragon piece matching one of the colors... whew... you'll be sending lots of blocks to your opponent.

BoraiCho ist my favorite Puzzle Karacter because his Kollapse is very effective and one is able to perform it very often during a match.
Stage? hM dunno I have no favorite. I like almost all of them.

Charecter: Raiden. It was already said but he's got one of the best moves to screw someone over with, Storm. If I get stuck I'll switch to Kabal, who is arguable the best charecter to use if you use the double bomb technique on two different colors.
As for stages: I like the dead pool, slaughterhouse, and ying yang island Those have to be the best three finishers.