I would suggest having a read of
this for some well written descriptions of the technologies.
Indeed, IPS would be better for watching videos than a TN panel, response time will be not an issue with modern IPS monitors playing video content (look for less than 10ms, almost all are). However, some of the VA technologies offer even better black levels that IPS - so they would also be very good for video watching.
Finally, it is also worth considering a proper TV if you are mainly watching videos and and considering paying the premium for an IPS monitor. So long as you get one with a 1080p resolution and a decent write-up the viewing experiece will likely be better than a PC monitor, mainly due to the size. Many of the LCD TVs do use IPS or VA panels, they just use much larger pixel pitches than in PC monitors.