I was just thinking today about the frequency of use of maneuvers in my GURPS games. Based on what I've seen, not a hard count, this is the breakdown.
Most frequent use: Attack, Concentrate, Feint, Long Action, Move, Ready, Wait
Frequent use: Aim, All-Out Attack, Change Position, Committed Attack, Do Nothing, Move and Attack
Occasional use: All-Out Defense
Rare used: Defensive Attack
No use: Evaluate
No matter what I've done with Evaluate, no one uses it. Defensive Attack is something I like, but rarely does anyone want the bonus to defenses but still want to attack - All-Out Defense is a more popular choice if defense is important. That one doesn't come up all the time - maybe 1-2 times per combat from, mostly, non-combatant types who are close to being attacked. The offensive-heavy ones come up a lot, and the balanced attack and defense approaches the most.
How about in your games? What sees the most use, less use, and no use?