For the record, the PAL format is actually a later technology than NTSC and it technically superior.
In simple terms, PAL looks cleaner and sharper, even with games. Primarily because of ther higher resolution, secondly because it's a more refined format. NTSC refreshes faster, but always looks 'softer' and a little blurry. NTSC can actually look quite nasty if you have a decent PAL optimised game...
It depends what you need it for... with a TV program, PAL is the best format to use. It looks cleaner and sharper, and the fps difference is small (25fps on PAL, 29.95 on NTSC). If you want to make TV shows, use PAL.
Games are different. Games these days often run at 60fps, and thus the 50Hz refresh rate of the PAL system acts as a bottleneck, so even with PAL optimisation you can loose as much as 10fps.
Because of this, many developers choose to add 60Hz modes into games, mainly GameCube games.
Things weren't as bad in the days of the Saturn and Genesis, where nothing really went over 30fps anyway. Which is why Saturn PAL Optimised games look FAR superior to the equivelent NTSC title. So games should generally use NTSC these days, because the drop in fps in PAL overshadows the clearness of PAL.
I'm not too sure what the difference is between PAL and SECAM mind... presumably it's colour encoding...
For the record, the difference in power between the regions is unrelated.