All I really HAVE to have is Reverb. That's really all, just Reverb and I'm good. Just a Friedman and some good Reverb.
Other than that, Delay is the next thing, followed by Wah, Chorus, Harmonizer, Phaser, Flanger.
That's really it.
Reverb is the only thing I absolutely need.
The rest of that I listed is just something to sprinkle on from time to time in moderation.
If all I had was a distorted amptone and Reverb though, I'd be satisfied.
I'm not much of a effects guy... I think they are overrated.