steal a skill
Infiltrator’s Strike from Thief to Warrior, replacing Hamstring.
I’ve got five characters at 80. Most of them I’m very happy with, though it did take me a while to learn to appreciate the Engineer’s rifle skill set.
But I would, without hesitation, put the replace my Guardian’s Shield of Absorption with the Warrior’s Shield Stance. I run the shield on my Guardian for aekittenetic purposes; otherwise I’d run the focus for my off-hand. I’m sure SoA has its uses (particularly in WvW), but I’m primarily a PvEer and find I rarely use it at all. Outside a few very rare circumstances it’s all but useless in PvE. And Shield Stance is a fantastic defensive skill against both melee and ranged attacks. That’s the one skill I’d steal, if I could.
This is a very deep question, so many possibilities I can’t think of anything real great, but I’d probably replace Ele’s fire touch with Guard’s GS 5. I can’t remember the name of the skill.
This is off the top of my head, anyway.
http://www.youtube.com/MangoMiner