Gomer Pyle, U.S.M.C.

Love it. Lots of great supporting characters like Duke, Sgt. Hacker and even Friendly Freddie, the con man.
The one episode that sticks out is when Gomer has to watch Sgt. Carter's car and make sure it doesn't get a scratch only to see it crushed by a wrecking ball.

It's a classic! Not too realistic as this was in the Marine Corps in the late '60's and Viet Nam never came up. That would kind of sour the comedy. It was funny, though!

Yes I have seen Gomer on The Andy Griffith Show.

I believe Jim Nabors once said that he could not watch the opening credits, as it reminded him of how many of those men he's marching with died in Vietnam.

GP is essentially Bilko, but with the emphasis uncertainly switched from Bilko to Doberman. Most of the best episodes could easily have been done on the earlier series by Phil Silvers. One of these, where Sgt Carter has sent Pyle on a dangerous training exercise and fears he may have been killed, features perhaps the most fascinating scene of the entire series: Carter has a guilt-induced nightmare where he is visited by a sleazy insurance agent/undertaker (also played by Nabors).

The is by far the furthest Nabors ever got from his comfort zone on the show -- he smirks throughout and laughs maniacally at the end until Carter wakes up.

First couple of seasons were funny, last couple, not so much.