I'm a big TNG fan. I was ten years old and saw it from start to finish. I've probably seen all episodes except for some in season two and seven at least thirty times. I think they've held up well. I enjoyed the nice mix of standalone stories and the fact that the series respected TOS but didn't feel weighted down by it. As a result the show had a nice mix of stories from high concept scifi to character stories.
I like *all* the cast as well as all the characters that includes the unfairly maligned Wesley Crusher and Lwaxana Troi.
Picard is my favorite captain and character followed closely by Data but I really like all of them pretty equally. Picard/Crusher and Riker/Troi were nice mature relationships. Data/LaForge is a great friendship. And Worf/Riker were a great manly man pairing. I also like it because I can remember what was going on in my life when each episode aired. Plus it was when Trek was fun and being a TNG fan was cool. There were all sorts of action figures, posters to collect. It was just a nice show I could look forward to each Saturday night.
I generally like almost every episode from season three through six. I also have found I tend to like even the episodes considered bad like Hero Worship, Imaginary Friend, Rascals, Genesis, Skin of Evil, Coming of Age, The Bonding, When the Bough Breaks, The Loss. I'm not sure if it is because I'm more forgiving or I just have diferent tastes from others. The Best of Both Worlds I&II is my favorite episode.
I enjoyed all the sci fi episodes like Clues, Conundrum, Power Play, The Game, Disaster, Cause & Effect, Parallels, Phantasms, Night Terrors, Remember Me, Future Imperfect, Timescape, Rascals to name a few. I also enjoy the more emotional ones like Skin of Evil, Silicon Avatar, The Survivors, The Defector, Dark Page, The Chase, Relics, Unification to name a few. To me All Good Things.. is the best Trek finale.
I also loved the bright interior sets and corridors. I loved the way the three chairs were side-by side representing the more egalitarian attitude of TNG. The ship is a beautiful sight, well designed and a believable evolution from the ones seen on TOS.