March of the Penguin - documentary and I wouldn't recommend too many on a "best of" list (unless the question was only on documentaries) and I think it's instant watch
Meet the Parents (I didn't care for the sequel as much)
Apollo 13
Roots - I was going to say this earlier, but it's such a heavy topic that I didn't.
John Q - Denzel Washington holds a hospital hostage until they agree to perform surgery on his son.
The Bourne series - see someone already mentioned them however
Harry Potter series
Lord of the Rings
Misery - It's older, but watch it if you've not seen it (it's also on instant)
Liar Liar - on instant
Jeff Dunham: Spark of Insanity
Jeff Dunham: Arguing with Myself - both of these are IMO, the best stand up comedy routines ever and both are on instant. I didn't care as much for the Christmas special he released last year.
Star Trek (2009) - I think this was a pretty risky move that could have been a huge disaster. People really take their Star Trek seriously. I just loved this and can't stress enough how well done it truly is.
Transformers - This is a series that is iffy. If you like the genre/theme you will LOVE them. If not, I highly suggest you pass. For us, these are must own films. The combination of humor, Sci-Fi and action are 2nd to none for my family.