Monks

[Arbitrarity]

As does the fighter on his fourth, unless we're saying the fighter has better than 24 str, which i grant may be likely. Assuming even attack stats (let's assume monk has intuitive attack), then the difference in their capabilities (15/15/15/10/5 vs 20/15/10/5 boils down to the one attack at +20 vs the two attacks at +15

Greater than 24 strength at level 20? Easy. Elite array gets 26, assuming you boost STR and get a +6 item. 38 is plausible, though not probable. (18 base, 4 race, 5 level, 5 tome, 6 item)