OK I ran some tests on our database to come up with this list for Black & White:
Unown learns Hidden Power by level, but not TM.
Wynaut and Wobbuffet learn Safeguard by level, but not TM.
Kricketot learns Struggle Bug by level, but not TM.
Burmy learns Hidden Power and Protect by level, but not TM.
Tynamo learns Charge Beam and Thunder Wave by level, but not TM.
There are several more for Gen 4 as well - mainly Pokemon that can learn Light Screen, Reflect or Safeguard via egg move. But also a couple others such as Totodile and Dragon Claw. But their evolutions can learn them so not sure any of these count.