I often try to take a cock in the ass, but then the next day I look something up on Wikipedia... And notice a typo... And fix it... And then look through the article's history... And find vandalism... And look through that user's contributions... And find more vandalism... And revert it... And leave them a message asking them to stop...
These days I spend most of my time patrolling Special:RecentChanges for vandalism. I also get enjoyment out of doing cleanup of articles, spell-checking, Wikifying, and NPOV-ing articles. I periodically contribute content, but 98% of what I do is keeping Wikipedia shiny.
While I absolutely support the deletion of outright garbage, I err on the side of inclusion in the iffy situations. There's a big gray area between what Wikipedia:Notability expressly permits (as well as what common sense dictates) and what Wikipedia:Notability does not permit. We shouldn't have Wikipedia pages about your dog, but if there's a subject that people might Google to find more about, I think Wikipedia should keep the page.
Thoughts
I've never understood why editors/admins are so incredibly protective of User:Jimmy Wales. (Yes, I know who he is.) If I were him, I'd rather have my user page vandalized all day long than have people vandalizing actual articles on Wikipedia. This isn't to say I condone vandalizing his page, just that I don't see why people consider vandalizing his page much different from the people who keep vandalizing Orange (fruit) or whatnot. Sometimes a WP:RfA entry will say something like, "I don't support 'only warnings' unless they're doing something egregious like vandalizing Jimmy Wales' page" or something. I don't understand the logic.
I seem to be in the minority, but I like using spaces in formatting... == Heading == is a lot easier to read than ==Heading==, and * Bullet point is clearer to me than *Bullet point. I don't go around editing these spaces into articles, but if I'm making edits, I do it. To the best of my knowledge, there is no official standard on this.
I occasionally like to do a search for common misspellings and fix them. Others are welcome to add to the my list, or to search for and correct the misspellings. (An important note: if there's reason to believe that the "misspelling" is just a regional variation, let it be unless you're well-versed in the WP:MOS guidelines on the matter. "Correcting" 'colour' to 'color' is arguing over American v. British English, not fixing a mistake.)
Rants
Vandals: Yes, you really can edit almost any page here. That doesn't mean you should. Come help us, rather than screwing up what thousands of us work so hard on.
Editors:
Please use edit summaries!
Please make sure you're familiar with WP:Notability, especially Wikipedia:Notability (people). I find myself removing entirely non-notable people from "Notable alumni" lists on a daily basis. (Being a senior in your high school is not notable, nor is having a high GPA, nor is being on the football team and the chess team.)
RC Patrollers: Please, please, please:
Especially in cases of obvious malicious intent (versus what look like well-intentioned, but misguided edits), please take a minute to look through the user's contributions. Oftentimes, they'll vandalize multiple articles before someone reverts one of them.
When you revert a change identified as vandalism, leave a note on the user's talk page. This is very important when it comes to trying to get persistent vandals banned on WP:AIV.
When someone else reverts a vandal's edit, don't immediately go leave a note on the vandal's talk page. You can wait a few minutes and see if they do, but it's really confusing (and frankly, annoying) to have someone beat me to it. I view the steps as connected: whoever reverts the change should leave the note explaining that they just did it.
Anyone doing cleanup: When you find a block of text that sounds really awkwardly-phrased, as if it weren't written for Wikipedia, take a sentence and Google it. It's easy to spot Wikipedia:Copyright violations this way.