Hmm, top 20, I don't know, let's see if I can think of 20 favorites:
Rating: 5 out of 5:
1. Where no one has gone before. To me, this IS TNG. I only wish this episode was a two parter, and that it had been done in the 2nd or 3rd seasons, so the characters would be more comfortable in their skins. (The movie Sphere is quite like this episode, but ended horribly lol)
2. Remember Me. Great followup to the traveller, great use of Beverly Crusher, who is my favorite female character in TNG, great Sci-Fi story, great line "if there's nothing wrong with me, maybe there's something wrong with the universe!" lol. The spacedock is icing on the cake
3. Contagion. Great tension, and loved the "Stargate" (before there was a Stargate). Would have been interesting to have Picard or Data step thru the gate (and a follow up story in search for them?) otherwise great episode.
4. Q Who. Perfect episode, great use of Q, great "oh shit we're fucked" ending.
5. Best of both worlds pt1 and pt2. Only suffered from lack of more special fx (perhaps a peek at the Wolf 359 battle?)
6. Who watches the watchers. Great piece of morality in a sci-fi story.
Rating 4 out of 5:
7. We'll always have paris. Love the sci-fi angle. The Picard love story brought it down a notch though.
8. Where silence has lease. Creepy episode. Only bogged down by the lack of shoving a photon torpedo up Nagilum's ass. At least they had the balls to risk destruction in defiance to him though.
9. Cause and effect. Great Sci-Fi episode. Loved it, but felt the ending was lacking somewhat. It was just basically (wow, we've been in a loop for 17 days? oh well, shake it off and let's keep on moving)
10. Night Terrors. Great episode, but two things hurt the story: Deana's big ass, and the fact that they didn't meet the other aliens face to face

. The scene with Beverly in sick bay with all the corpses sitting up always scares the crap outta me.
11. Parallels. Great episode. To me what hurt it was the fact that they ended up destroying the other Riker (from the timeline where the Borg had won). Should have rescued him instead or something.
12. Schisms. Another great creepy episode. Loved the bit where Riker phasers down one of the Aliens, but it wasn't enough, they should have send a team to blow the bastards up lol
13. Relics. Great cameo from Scotty, great story with the Dyson Sphere. Only thing that sucked is that they didn't explore the surface
14. Tin man. Great A story, great B story. Only thing that sucked is that they lost the Tin Man. They should have convinced it to go with them into Federation space.
15. Timescape was great, but something is lacking, I can't put my finger on it, so it gets 4 out of 5.
16. Tapestry. Great episode, but I hate the Nausicans lol, Picard should have stabbed them back lol.
17. Emergence. Had some really good ideas with the imagery, but it too is lacking something.
18. All Good Things. Excellent two parter, but if Picard was going to marry Crusher, they should have stayed married, and my favorite Refit Galaxy class may never come to existance in the "real" Trek universe
19. Frame of mind was excellent, but one of the only times Data kicked ass never actually happened (it was in Riker's mind

)
20. Sub Rosa. Only for 2 reasons: 1. I like to laugh at the Scottish guy "Dae Naught Laigh tha Kaandle!!", and 2. watching Beverly have an orgasm. Yes, that saves the entire horrid episode lol