I appreciate you holding down the fort over there. As I said before, I don't expect a lot of cross-over fans with Pathfinder proper.
So while I'm happy to answer actual questions wherever I am aware of them, I don't want to have to engage "pure preference" posts in multiple locations.
I think the best way to compare the fighter and barbarian is to just look specifically at the levels where the fighter gets his main class feature, expert weapon proficiency. Let's assume that both focus on the greataxe.
I'm going to try to keep them on parity with the same basic feat choices, showing crossovers, and "unanswered" feats and class features.
Code:
Level Character Feats Fighter Feats Barbarian Feats
3 1st, 3rd 1st, 2nd 3rd
7 6th 4th, 6th 6th
11 9th 8th, 10th 9th
15 12th, 15th 12th, 14th 12th, 15th
19 18th 16th, 18th 18th
By 3rd level, both the fighter and the barbarian can have weapon focus, power attack, and cleave. The fighter has one more character feat left over.
Beyond that, the fighter can use his character feats to keep up feat-for-feat with whatever the barbarian takes from his bonus feats. The barbarian can use his character feats to keep up with the fighter's bonus feats-- for 7/10 of them. (The fighter has 18 feats overall; the barbarian has 13 feats.)
By 20th level, the "unanswered" comparison is as follows:
FIGHTER
1 character feat
4 fighter feats
5 expert weapon proficiencies
+5d6 punishing strike
BARBARIAN
Fast movement
Rage (through mighty), 6/rest
Uncanny dodge (improved)
DR10
Indomitable Will
Trap sense +6
The divergence at the end of the line tips the edge in offense to the fighter (expert weapon profs, more feats), and the edge in defense to the barbarian (DR, uncanny dodge, indomitable will).
Especially illustrative is the difference between the fighter's greataxe and the barbarian's greataxe:
Code:
Expert Weapon Proficiency (Greataxe)
3rd Critical threat range to 19-20
7th Critical threat range to 18-20
11th Critical multiplier to x4 (likely now 15-20 with Improved Crit)
15th Increase damage to 2d8
19th Add reach, trip, etc.
Fortunately I think you'll see more divergence between the fighter and the barbarian that this "Keeping up with Jones" example illustrates.