+1
I can't recommend Dungeon Fantasy enough. It's built upon the extensive toolkit which GURPS provides, but with more focus on the style of fantasy which I was familiar with via d20 games. I've found that -for me- it strikes a pretty good middle ground between what I've come to enjoy from GURPS, and the elements of D&D and Pathfinder that I like. Thirdly, with the mentality that GURPS is built upon and leans toward, I've found that it's fairly easy to convert old D&D adventures to GURPS Dungeon Fantasy once you get the hang of the system; the mechanics are different, but some of the spirit behind the product is similar enough that it feels right in play.
There are some pretty good blogs about using Dungeon Fantasy. One is here: http://dungeonfantastic.blogspot.co...00-04:00&max-results=7&start=35&by-date=false
This part links to session info: http://dungeonfantastic.blogspot.com/p/my-df-campaign.html
Here's a blog about running The Temple of Elemental Evil using GURPS: http://d20to3d6.blogspot.com/
Ill throw my hat in and say Mutants and Masterminds. Though geared towards a super hero game, it really is genreless. You can run pretty much anything. It's easier to understand than HERO and a lot quicker to play. (I loves me some hero, dont get me wrong)
Note that Mutants & Masterminds, now in its third edition, is derived from the D20 OGL, as are Green Ronin's Blue Rose and True 20. Warriors and Warlocks is the fantasy supplement for M&M2e: http://www.amazon.com/Mutants-Masterminds-Warriors-Warlocks-Sourcebook/dp/1934547190
Let us know if you decide to go that route; if not, I can make another suggestion or two.I forgot to mention that. I was recently introduced to 3e and it looks pretty good. The action has an appropriately heroic feel as far as I can tell, but I have only run a couple of short combat playtests.
Let us know if you decide to go that route; if not, I can make another suggestion or two.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.