I own Star Fox, 64, and Adventures. I also rented and completely beat Assault. I've yet to play Command.
RANK:
4. Star Fox
It's a great old title, ahead of its time, and excellent for nostalgia. Unfortunately, as a game, it's not quite as good as the others, mostly because it just doesn't have as much stuff. What's there is excellent though, and I'd play it again in a heartbeat.
3. Star Fox Assault
Kinda underrated, though I can see why some people wouldn't like the on-land segments, especially since the LandMaster switched from the on-rail goodness in SF64 to a free-roaming vehicle. Still, the game was fun, the Medals provided me with a better challenge than I'd had in a while and helped lengthen playtime, and the story was decent enough. At least it went beyond "Andross and his underlings are being jerks. Go kick their ass."
2. Star Fox Adventures
REALLY underrated. I got this to help shorten the wait for The Legend of Zelda: The Wind Waker. It ended up feeling like some kind of Zelda sidequest. Some kind of AWESOME Zelda sidequest. Now, considering it drew pretty heavily from Zelda, there were a couple of flaws; simple combat system, laughable NPC voice acting (this is why Hyrule should remain mute), kinda on the short side, not alot beyond the main story(another decent one, by the way), not many intuitive puzzles, dissappointing final boss. Most of it gets easier to swallow once I remember it's not actually a Zelda game. I kinda raise my standards when Zelda comes up. Anyway, good stuff: Beautiful graphics, great gameplay, good voice acting for Fox and Prince Tricky, good boss battles, a nice reunion during the final fight that help ease the pain of dissappointment that comes with the true enemy's identity, nifty staff upgrades, a good soundtrack, and just fun in general make this one of my favourite 'Cube titles. I'm actually in the middle of another playthrough at the moment(well, not this moment)
1. Star Fox 64
Greatness in cartridge form. The excellent gameplay of the original beefed up with better graphics, more levels, more bosses, more vehicles, more enemies, more secrets, temporary allies(Katt and Bill), a rival team(Star Wolf), voice acting, analogue control, multiplayer, expert mode, charged shots… In short, the game is pure 100% excellence. Truly, one who has not played it is one to be pitied. I mentioned the simple story earlier, but you know what? When the game is this insanely fun, the story means precisely zilch.