IPS is a superior and costlier technology. It mainly focuses on colour and IPS panels have some of the widest colour gamuts.
TN is basically a value technology. Although some feel TN panels are getting closer to their peers (IPS, MVA, PVA), TN remains inferior in terms of contrast ratio and especially viewing angles.
IPS did have issues with pixel response, but revisions and S-IPS made this better.
Personally I have found MVA panels to offer superb contrast ratios, better than IPS and PVA and this is often more important for multimedia users (movies, gaming) than colour purity.
Dinesh has obviously never used a P-MVA panel...
^ your sig - India died after "indepedence"? Or did you mean impedance? We should've gone tubes
^^For gaming TN is better? Yeah right. Shitty viewing angles are only acceptable for 19-inch monitors and below, after that it gets downright annoying...