Every original episode is about 30 minutes long, which is too long to be aired on TV as a whole, so bits are edited out. As far as I know, the Region 2 DVD box sets (that is the European ones) contain episodes in their TV-form, so if you've only watched the show on television up to now, you won't spot any difference. The American version, however, exclusively includes the original 'director's cut' episodes instead, with about a minute more on each episode. I have seen a few original episodes against edited ones, and if you ask me, the difference is only very slight. Doesn't change the fact that Friends is the best comedy series out there and a must-have! So YES, go for it!