Ya know, I actually love pretty much everything about making characters. I have notebooks full of them from older editions and these days, w/the CB, I just logon and make some stuff and save the ones I really enjoy. It's pretty rare that I have a specific character idea before I sit down. Oh I might know that I want a halfling rogue, but I have no plans in my head about personality and such first. Especially since prior to 4E we were always using dice to generate stats.
Once I had the stats and started placing them, picking skills, looking at feats, I usually begin forming some solid ideas about their personality and how they approach things. For example, I've made a number of different characters for an upcoming run at Revenge of the Giants. Partially this is b/c our group has kept shifting character plans, but then we picked up another friend. Unfortunately, we all sort of expect her to flake on the game, and her being a rogue, is one of only 2 Strikers planned for the group of 6 players. Tiefling Warlock, Human Cleric, Dwarf Fighter, either a Wizard or Artificer for one guy, and my Gnome Bard. If our Rogue drops out, I have a Minotaur Fighter focused on charging who would be fun as well as a Daggermaster rogue. He started as a defensively minded rogue, then morphed into a less defensive, but very mobile and focused against Large+ targets. Lost in the Crowd and Underfoot, plus the Close Quarters daily utility and the fact that we all know we will be fighting lots of giants led me to make his surname Hamstringer
His personality may have come about last, but the mechanics and stats suggested various ideas and I kind of ran with them. Haven't decided if he has a personal vendetta against giants due to a family death by them or if he was just one of his village's protectors against some nearby giants. The first could make him a bit more reckless and fighting at all costs, the latter could suggest he's more surgical in his attacks. Not sure how he should be yet.
I agree w/AeroDm tho. Optimization is great fun. Having a general idea, seeing a feat that makes you go "OOooohhhh!" and instantly scrap several feats so you can re-focus around it is very cool. Sometimes you just make a change in your diety or pick up a random feat like one of the Marks and realize you now qualify for something very neat. I was working on an illusionist wizard last night and was reading a page about wizards and they mentioned the Phiarlan Phantasmist as a suggested PP. I didn't see it listed tho, so I pulled out my book and realized I needed the Mark of Shadow to qualify. So I dropped a feat and read the PP and realized that it would be a very nice touch. Fun discoveries like that are always nice.