When you say "know", do you mean "know of", or "can perform"? I know of about two hundred different shift variants, I can execute maybe fifty or so to some extent, but the ones that I would consider using in front of people are:
1. Classic pass (various handlings: riffle, dribble, etc.)
2. Herrmann/Hofzinser pass (various handlings: turnover, Midnight Shift, etc.)
3. Erdnase Shift, One Hand (I haven't been able to get the two-handed version to look natural so far)
4. SWE Shift
5. Longitudinal Shift (both handlings)
6. Open Shift (both handlings)
7. Charlier Pass
8. Hoffman/Sachs one-hand shift (not its real name, but it's taught in Modern Magic and Sleight of Hand so I call it that as it doesn't have another name, as far as I know)