I, like many of you, spent hours reading through Deities & Demigods. The illustrations, the descriptions, the powers, the follower-specific info - so much to digest! I have a particular affinity for the Norse and Finnish mythos, thanks to my Danish heritage. Then there's the Greek gods, I may have heard about one or two of them before in the books of my youth. And I find myself drawn to the Egyptian mythos, especially Bast, the cat goddess. I have always been a cat person, but don't tell my dogs - they wouldn't understand. In our 3.5 FR campaign, there's no shortage of info on the various gods of Faerun, and they play a vital role in the big picture.
So my pick is Garl Glittergold as described in Deities & Demigods (page 109). I have played a couple of gnomes here and there, and I always felt like Garl had my back, you know? Other than that, I really don't have a compelling reason to pick him other than I like his write-up, attributes, and of course the Jeff Dee illustration.
Runner-up would be Gruumsh (Mike at Swords & Dorkery and I seem to think alike on some issues). I really like this snippet from DDG: "To become a shaman of Gruumsh, an orc must pluck out his own left eye." Gah!
Honorable Mention goes to Blibdoolpoolp, mostly due to her nigh-unpronounceable name. A nekkid chick with a lobster head and claws? Eww. I really hate fighting kuo-toans. They are nasty, tricky, tough foes, so it's fitting their goddess is equally vile.