I haven't played SP in awhile, so I have to go with the battles that stick in my mind (okay more like that I can remember) which obviously must have had the better impact.
The two battles that stick in my mind best were those between Boc and Jerec.
The other was the battle with Maw, but question with this one. Did you battle Maw and a Force using dude (can't remember if that is Pic or Gorc) then fight then at the same time. Cause this one battle sticks out in my mind fighting the two at the same time, if that's not in the game then I guess it must have been a DL, or something my mind made up :/ which I....wouldn't rule out. lol.