The paladin one (Charging Smite) is a killer!
A 10th-level Paladin that performs a Charging Smite while riding (even a regular horse), with the Spirited Charge feat deals 3 x 1d8 (lance) + (Str bonus) + (Magic Bonus) + 10 (Smite Evil) + 20 (Charging Smite). If Str is 18 and the lance is +2, you're looking at 3d8 + 12 + 6 + 30 + 60, or 3d8+108 points of damage. On a critical hit the damage jumps to 4d8+144. Slap on Cavalier levels and you're looking at attacks capable of exploding a dragon, even if the horse is unlikely to survive the battle.