Hey Watt,
It comes down to two things really, your budget and room/weight you'd like to carry. A standard [good quality] compressor with an air tank is a good all round compromise. If you use lots of air often, you might consider a bigger capacity compressor and larger tank.
Your basic 12V compressor may only put out 1 cubic foot of air, where some of the premium ones will do nearly 4. Converting an airconditioning compressor [yourself or purchasing it as a kit] is an option if you pump up lots of tyres, run air tools etc [some do 8+ Cu ft].
If you do your tyres once every month or less, then one of the better quality basic compressors will be fine [just be patient].
If you don't use it often, consider getting a portable one [they come in a plastic tool box]. It can be handy to move it around and swap it into different vehicles.
Let me know if you'd like to know anymore...
Cheers