If your interested in looking around a solid example, you're more than welcome to come and have a look at mine.
Main points to look for:
Rust - you'll notice many threads on here about rotten cars, it is very important you look EVERYWHERE! Sills, floors, suspension mounts, boot floor. Front wings often go rotten around the leading edge and aren't cheap to replace properly. Most 944s look good on the outside.
Engine and drivetrain - the car should run at 2.5bar oil pressure once it is warm. It should be very quick to go up to 4.5/5bar on start up and when on the move, whilst moving it should not really drop from this. Each gear should engage positively and shouldn't have a massive amount of slop (but it's not anywhere as direct as an MGB for instance) it certainly should be an improvement on a 911 though! Make sure reverse engages positively and doesn't jump out of gear. If the car is fitted with power steering they are notorious for leaks - it can be a better option to just swap it out for a manual rack.
Interior - most are terrible! Dashes crack, seats are often ripped / worn badly and trim is not cheap to replace!