Have you seen that episode?

We're getting crap, and stuff like Jurassic Bark and Buffy the Vampire Slayer is untouchable. Come one guys. There's more than enough great episodes out there for everyone.

That episode for Fresh Prince along when will was shot trying pushing Carlton out of the way was a very sad episode, and it still managed to have a lot of laughs. They also have one of the more satisfying finales ever on tv.

The borg on Star Trek TNG was so good they got their own theatrical movie, so obviously that was a big one.
Back to Quantam Leap, the episode when he tries to save his brother's life in Vietnam after leaping into a younger version of himself the episode before was one saddest, and touching arc ever especially when you consider the twist

X-Men The animated series version of Days of Future Past 2 parter was one my favorite things ever as a kid. I'm excited to see the upcoming film version.

Well that's not true, The Fugitive finale was seen by 25.7m households compared to 50.2m households for the MASH finale (among a whole slew of other programs that were also watched by a greater number of households than The Fugitive finale). Did you mean household rating? Which is really just a percentage of the total households in America that own a TV set There it's closer, but even then MASH is on top (60.2% vs. 45.9%).

I do believe the highest household rating in Nielsen's history was Elvis Presley's appearance on the Ed Sullivan show in 1956 (82.6%) but obviously it was a lot easier to capture a higher percentage of the population that owned TVs back then (I Love Lucy's 2nd season averaged a 67.6% rating for all episodes, lol, today a program is a blockbuster with a 13.0% average household rating). Conversely, though, it became easier to set viewership records up through the 80s due to increased TV-owning population/general population growth -- e.g., that 82.6% rating back in 1956 translated into "only" 60m viewers whereas the 60.2% rating from MASH in 1983 resulted in 105m viewers.

And now of course since the peak of viewership back in the 80s the decentralization of TV (and entertainment options in general) has caused viewership to be diffused, and stuff like DVR only hastened that decline of both measures (household ratings and number of viewers).

"Bart Gets an F" is the most-watched Simpsons episode in history (33.6m viewers | 18.4% household rating), though, and I'm fairly certain it's the most-watched scripted program in FOX history as well.