Ok, I'll go on record with my round-by-round and anyone that disagrees can challenge my way of thinking and make a solid argument as to how I'm wrong:
Round 1: Pacman 10-9
Feel out round, slow start, Pacquiao more aggressive and lands more shots, Marquez landed a few nice crisp counters, Pacquiao however also showed good defense and blocked and dodged many punches. Pacman gets the round.
Round 2: Marquez 9-10
Marquez simply outworked Pacquiao, landed more shots, good counters and finished off the round with a huge shot that rocked Pacquiao whose legs clearly buckled.
Round 3: Pacman: 10-8
Pacquiao scores huge knockdown. 10-8 round.
Round 4: Pacman 10-9
Pretty close round but Pacquiao was the aggressor, landed the bigger shots and controlled the tempo. Marquez landed some real nice counters punches, but counter punching alone will not win a round. Pacman gets the round.
Round 5: Marquez 9-10
Much like round 2, Marquez simply outworks Pacquiao; lands more shots, harder and cleaner punches.
Round 6: Marquez 9-10
Marquez simply out-boxes Pacquiao. Pacauiao doesn't land any significant punches, Marquez lands several. Easy round for Marquez.
Round 7: Marquez 9-10
Really tough round to score, could have gone either way. The first half of the round neither fighter did anything, the second half both fighters were throwing serious bombs and exchanging big shots, Marquez I thought got the better of the exchanges and was able to win the round.
Round 8: Marquez 9-10
Easiest round for Marquez. Pacquiao gets a nasty cut on his eyelid caused by a Marquez punch, which clearly bothers Pacquiao and we can see him squinting and trying to wipe the blood out of his eye on several occasions. Marquez takes full advantage of this and lands shots pretty much at will.
Round 9: Pacman 10-9
The corner does a great job stopping the blood of Pacquiao's eye. Pacman was more aggressive and landed the bigger shots. Marquez has a late furry in the closing seconds, but not enough to steal the round.
Round 10: Pacman 10-9
Easiest round for Pacquiao. Marquez develops a new cut on his eye which clearly bothers him. Marquez nearly goes down early in the round from a huge left hand from Pacauaio which sends Marquez stumbling in the ropes. Marquez recovers, but Pacauaio controls the tempo of the round and lands bigger shots. Pacman gets the round.
Round 11: Pacman 10-9
Pretty close round, both land some big shots, pacman finishes off very strong which is enough to steal the round.
Round 12: Marquez 9-10
Similar to round 11 with both men willing to exchange and go toe to toe, Marquez however gets the better of Pacquiao on most of the exchanges and shows better defense by making Pacauiao miss.
Final score: 114-113
6 rounds to Pacquiao
6 rounds to Marquez
The difference being the knockdown.