Hmm... I don't often think about a character I'm interested in playing until I'm actually on the verge of needing a character to play. But let's see...
It seems like my M.O. as a player is frequently a combat-focused character, but not just a plain fighter (because they're boring.) I've done a lot of ranger/barbarians, and ranger/fighters, and other martial type prestige classes to give myself a little more variety.
My second most likely pick is some variety of rogue.
But honestly, for both of these, what I'm excited to do with them is to adapt or adopt some of the Pathfinder class archetypes into 3.5 and use them (most of them can be adopted straight with no modification, at least with the ranger and rogue, since the classes are so similar in structure between the two games.)
Yeah; I know, I know. Why am I excited to run a character that's basically the same as the characters I've already run, with only minor variation? Frankly, I just don't really like magical classes. I don't mind some minor supernatural variants, but I don't want "full-time" spellcasters.
I could also play a soulknife, or lurk, or even psychic warrior. What race? Either human, or something a little more outre. If I do end up playing a psionic class, I'd probably pair it with a psionic race, like elan or kalashtar. Otherwise, I'd play around with some other type race. I've always liked shifters, and I'd like to find a good LA +0 version of the classic planetouched races, like tiefling and aasimar. In fact, I've got some other really cool ideas based, again, on some Paizo subsitution of alternate abilities that I'd like to entertain. There's some Paizo rogue class abilities, which I've converted to feats as house-rules for me, that if I can get my next DM to allow, I'd also like to use. They allow for some very minor spellcasting abilities, and even a familiar for non-magical classes. I think being able to cast a couple 0-level and 1-st level spells, and have a little monkey familiar or something (or maybe an imp, if I take two feats to get an improved one) would be fun for a character who's otherwise not really a spellcaster. In fact, if I gave it to a swashbucklerish character, it would give him a real Gray Mouser type flair.
That said, I have no idea when I'll be playing D&D again, and I'm not really in the habit of planning characters that I'm not even playing well in advance of having a campaign in which I would play them.