Vegeta is not only my favorite Dragonball character, but also my favorite anime character of all time. I tend to gravitate towards the villains/badasses of the shows I watch, so it's no surprise that Vegeta became an instant favorite of mine. When I first started watching DBZ sometime in 1997, the first episodes I saw were when he was running around on Namek being a dick to Freeza's minions. Though it's hard to remember the exact first episode I saw, based on how the image stuck instantly in my head, I would have to say it was probably the episode where he's bullying Dodoria. I was like, damn, this short guy's making a total bitch of this pink blob who's, like, twice his size! All while wearing this badass smirk. I was instantly in love

When Cartoon Network re-aired the beginning of DBZ (in early 1999?), I finally got to see how Vegeta's story had started (while watching the Namek episodes, I had no idea why he always used Kakarrot instead of Gokuu), and the love only deepened. I just admired the tenacity he showed during his fight against the Earthlings, how even with all the shit being hurled at him, he just kept going.
Later, when I found out about his relationship with Bulma, it added another layer of interest in his character (can't stop that shipping instinct

). It was like, bam, out of nowhere, he suddenly had a family. However, it's not like his character underwent an instant transformation into a family man, which was appropriate. It would have been weird for a guy to him to suddenly be all like, "I love Bulma, and I love our son! Forget my training, let's all go out for a family picnic!" (a lot of fanfics seem to go with the fantasy that Trunks was actually
planned, though

). His development happens in stages, and I think a big contributor to it was when future Trunks died in front of him. Vegeta's had his share of rage-filled freakouts over the course of the show, but that was the first one that was fueled by something that happened to another person, rather than himself. I honestly wonder if he would have gotten back together with Bulma again and started being a father to baby Trunks if he'd never been forced to realize his emotions like that. I know a lot of people complain about Vegeta's asshattery during the Cell saga, but it doesn't really bother me, honestly. He still had some great moments and great fights during that time period, so he's forgiven for a little excessive whining.
During the Boo saga, we get to see the result of the previous buildup of character development. Though he regressed when he let Babidi possess him (and gave the most badass evil grin
ever 
), in the end, he sacrificed everything in order to protect his loved ones. He even gave up his pursuit of trying to be better than Gokuu. The most telling evidence of his transformation is to compare his views of how he wants the dragon balls to be used. At his first appearance, he wants to use them selfishly, to gain immortality and rule the universe. At the end of the series, he uses them to save everyone. Quite a turnaround, I'd say.
As for GT....leather pants = hella sexy. Freddy Mercury mustache = SO NOT sexy. Vegeta seemed to be more comic relief in GT (I think he had all of the funniest moments!), since Toei was too busy fapping to Gokuu to bother making anyone else useful. I did like his episode where he basically reflected on his own character development (as a bonus, he had cute interactions with Bulma in that episode, too). But anyway that's my take on the man who went from being a Giant Monkey to a big pussy
