Every year, my wife and I go see all the movies that get a nomination in one of the "major" 6 categories: actor/actress, supporting actor/actress, picture, and director. We usually start by seeing a lot of movies in December before the nominations come out. We do this to have fun on Oscar night, to have fun seeing movies, and as an excuse to see movies we might otherwise skip. We have been surprised by some wonderful movies this way.
So far this year we have seen a lot. These are ones we saw that might be involved in the major nominations. They are all worth seeing:
Slumdog Millionaire, Gran Torino, Benjamin Button, The Reader, The Wrestler, Revolutionary Road, Frost/Nixon, Wall-E, Batman, Milk, and maybe something else I can't remember. We haven't seen Doubt yet.
FWIW, I agree with both no_vas and ISM. Here are my opinions on these movies. It is worth what you are paying for it.
Slumdog was the best of these movies, in that it was the most emotional and was easy to connect to. If you see this movie and don't get emotional, you are stone. If you only see one movie this year, make it this one. The director has done movies in a wide variety of genres, and most of them are really good.
While watching Benjamin Button, it felt like a copy of Forest Gump to me. Afterwards, I saw that it was written by the same guy. The movie was beautiful looking, but I didn't emotionally connect to it. I wanted it to say something profound, but it didn't. A movie about living life backwards seems ripe for something to say, but this movie was "just" a romance. That would be fine, but I was expecting more. I don't think Pitt is a good enough actor to elevate the movie.
Gran Torino, The Reader, The Wrestler, Revolutionary Road, and Wall-E are the best of the rest. Clint Eastwood, Kate Winslet (x2), Leonardo DiCaprio, Mickey Rourke, and Marisa Tomei did amazing acting jobs. Milk was a good movie, but not as good as these others. Sean Penn was fantastic in it. He can be annoying, but he wasn't here - he was great. Wall-E was a great movie and is my second choice for best picture. Frost/Nixon was interesting, but wasn't one I emotionally connected to. Heath Ledger was great as the Joker, but otherwise Batman was just so-so.