cloth for sure. I've owned cars with both and like my cloth interiors better now!
-Better to keep you in the seat while cornering.
-Not so hot in summer (even with tint)
-Winter doesn't really make a big deal
-Most cars with leather "seating" area have vinyl sides/backs which end up cracking and look like shit, plus the "sat in" look on the actual leather.
I'd only get leather on my next car if it was a luxury car that I didn't plan on keeping more than 5 yrs.