Have a read here:
http://www.tomshardware.co.uk/monitor-buying-guide,review-33576.html#p1
Broadly:
TN: Fastest but lower colour quality and viewing angles than IPS or VA based panels, best suited for fast gaming.
IPS: Slower than TN but better colours and viewing angles, usually more expensive, although that varies a lot, best suited for more gentle gaming, general uses movies/entertainments faster panels match TN for speed but at a cost.
VA: Slowest but superb colours and unrivalled contrast, as with IPS, wide viewing angles. Few fast ones out there so it's mainly aimed at pro users who demand the highest colour fidelity. Excellent for general uses and movies but not so good for fast paced games.