Thing with Ken.. he can get 8 hit combo with kicks (down + weakest kick). The enemy gets pushed away from you, so the timing of your presses has to be very good or you'll be pushed too far apart before 6 or 7 hits. I did 9 hits with this once, and I think 9 is the max possible this way (even 7 and 8 require lots of save states).
If you can chain this on top of another combo, you can perhaps get over 10 hits. I used Saturn's Sagat fight, and half-way through his 8-hit combo I started doing some low kicks and got 10 hits. I think more than 10 would be possible this way.
Here's a quick movie I made a few days ago. I haven't played this version before, and I only really know the moves of two or three of the characters.. I really hate some of the characters since they never cooperate, so I just finished them quickly. Use Snes9x v6, with default checkboxes.
http://www.cse.unsw.edu.au/~alexpenev/my_ssf2.smv
Dhalsim: easy 7 hit combo (see?)
DeeJay: I went through one of his sonic booms. And the second one even hit me, but I didn't get damaged, hahaha!
Guile: going through some sonic booms.
Cammy: boring. If I high punch and she does a low kick, we both miss each other .. I just thought it was interesting to keep that in.
E Honda, Fei Long: boring
Zangief: simple 8-hit combo (Zangief is wider, so it's easier on him).
Hawk: boring (I really hate this guy! Die!)
Balrog: boring
Vega: I really hate this guy too, he's such a chicken. Round 2 is funnier in SF2 Turbo, since you can play at a faster speed and it looks crazier.
Sagat: 9 hits this time (he's really wide!).
Bison: some throws.
Desynchs: Cammy and Sagat may desynch. Just restart and fast forward.
Ok, someone try and get 11 or 12 hits now :)