Superman vs Black Adam, because that's simple enough, two burly brawlers and they're both in the DC Adventures Hero's Handbook, no going out looking for them.
This is also a comparatively simple fight, I'm not going to go and do any weird shenanigans, this is just punch, punch, punch, punch until someone is KOd.
Superman rolls Init +2 (14), BA rolls Init +6 (12), Superman first
Both have DC34 damage attacks
Speed is irrelevant in this fight, both have flight speed 15
Superman rolls attack 17 (6+11), which is a miss (BA Parry +11 = 21)
BA rolls attack 15 (2+13), misses (S Parry +10 = 20)
S rolls attack 23 (11+12), hits, BA rolls Tough 36 (18+18), no damage
BA attacks 19, miss (20)
S attacks 23, hit, 29 Tough (34-29), fail by 1 degree, 1 bruise = Tough 17
BA attacks 20, hit, 33, no damage
S attacks 16, miss
BA attacks 19, miss
S attacks 25, BA rolls 30, fail by 1 degree, Tough now 16
BA attacks 32, S rolls 20, fail by 3 degrees, staggered (dazed - only 1 standard action, hindered - half movement)
S attacks 29, BA rolls 28, fail by 2 degrees, dazed
BA attacks 31, S rolls 30, fail by 1 degree, Tough 17 (S recovers dazed)
S attacks 21, BA rolls 34, nothing (BA recovers dazed)
BA attacks 31, S rolls 36, nothing
S attacks 23, BA rolls 34, nothing
BA attacks 24, S rolls 24, fail by 2 degrees, dazed
S rolls 15, miss
BA rolls 26, S rolls 18, fail by 4 degrees, incapacitated
This was a relatively long fight mostly because of the whiffing and also because they're targeting each other's strongest defenses - just two men hitting each other as hard as they can.