A few recent additions, with the caveat that my comments will contain spoilers (as much as you can call something a "spoiler" for a movie that's been out for at least a couple decades):
MASH: Didn't really like it for reasons I explained above (it portraying a "shapshot" series of events as opposed to a "plot" story). Basically, a couple new doctors show up at medical camp, enjoy some juvenile antics and sexcapades, talk a guy out of suicide, spy on a woman in the shower, go to Japan to perform an operation and squeeze in some golf, and play a football game. The end. What? I think this is one of those films that was groundbreaking at the time but loses a great deal of its potency later when viewed in a different political and social climate.
Plus, am I really supposed to care about or like any of the main characters? I just found them to be cocky, delinquent, and juvenile. I wouldn't find those traits particularly endearing in main characters of a lowball college sex comedy or a Wayans Brothers movie, so I'm not sure why I should like it here, other than it's Elliot Gould and Donald Sutherland.
I'm guessing the TV series was better. I know I watched it as a kid, but I was too young to remember any of it. But it's got to be better than the movie though, although I'm pretty sure it was no Night Court. 
Doctor Zhivago: I kinda liked it in the end but was so-so on it throughout. A 3.5-hour epic love story set against the backdrop of the Russian Revolution of 1917. I know it's supposed to be an epic, but it didn't really feel like one. It just felt long. Unlike Lawrence of Arabia, which does feel epic because the character actually interacts with the parties around him and has a direct effect on certain events within the huge scope of things, that doesn't seem to be the case with Zhivago. It's a much more personal story of two people, but as such, you really don't feel much of the revolution itself.
I guess for an epic, I prefer something like Lawrence of Arabia or Lord of the Rings, where ordinary people are caught up in extraordinary events and actually have a hand in shaping them. Or they at least interact with them and are affected by them in a direct way or are personally trying to achieve something of epic proportions. That justifies a 3.5-hour running time. It's much harder for me to think of a love story that needs 3.5 hours to tell (Titanic may be an exception but only because I enjoy that movie for the utter chaos and panic of the ship going down and not for the love story itself).
With Zhivago, a couple meets, they lose each other, they find each other, they're separated, they find each other, they lose each other, etc, etc. Not much else really seems to happen. It does come together nicely in the end though, so at least it has that over MASH. Have I mentioned that I don't like MASH?
West Side Story: I'll admit I'm a sucker for a good musical, especially when its songs have permeated pop culture and are instantly recognizable and catchy. The first half hour or so of West Side Story, I was skeptical, since I had a very hard time buying a street gang like the Jets, given how they dance and how they dress. At least with Grease, the guys did both in a more masculine way, which made them believable as "tough guys." Not so much with the Jets.
But I eventually got over that as I got absorbed in the story, and it was a great story, which everyone knows is a modern take on Romeo and Juliet. It has some great songs like "America," "Maria," "I Feel Pretty," "Somewhere," and many others you'd probably recognize. Interestingly, a few days after watching the movie, I caught the Flight of the Conchords episode where they spoof the "Cool" song from West Side Story. I love when that happens.
