I sometimes find questions that are not suited for the site (usually because they are list questions), but I find interesting. Often times I upvote the question, and then cast a close vote. Does anyone else do this? Does anyone else think this is a bad practice?
Though it should probably be a rare occurrence, I don't see a major problem with this, because it's what we do anyway: we vote for what we like. If this practice is a problem, we have a BIGGER problem.
In more objective SE sites, upvoting means "you feel [it] is especially useful." This is the wording in our help, too, but only because it's a copy-paste. In more subjective SEs like ours, "useful" isn't a very... useful... term; questions about Star Trek aren't seeking solutions to a problem or in other ways looking for answers that are demonstrably "useful" to anyone except the original poster, so we can't use that criterion to gauge if it's appropriate to vote up or down.
So what does an upvote mean? PearsonArtPhoto says it means "you think it's a great question for this site," and that'd be swell... but we don't use upvotes to mean that, and if we should then we need to do a pretty strong education campaign about what makes questions great. (And I can't really think what downvoting would mean then: "This is an awful question for the site"? That's vote-to-close.)
No, we use votes as an indication of popularity: "I like this post" is much closer to what voting behavior means on scifi.se. We vote for the franchises we like, and the posts with lots of pictures, and we often don't even vote then (here's a post from a popular franchise with contemporary media saturation that got
13 14 votes out of over 1k views). If that's the accepted practice then I see no reason that just because the answer should be migrated we should make an exception to popularity-based voting for it. Heck, given the sickly state of our voting community, if somebody wants to vote on something at all I think it should be encouraged.
(And we shouldn't confuse up/downvotes with accepting an answer or voting to close; accepting an answer is the original poster's way of saying that one answer was more useful than the others to the original poster. If it were like voting, either upvoting would be one-per-thread or we could accept multiple answers. They're three different kinds of input about three distinct pieces of information.)
I must disagree with @Pearson's answer.
Closing means that you think that the question violates the site's "willing/able to answer this in SE format" rules, some/many established by community.
Voting means you like the question.
Therefore, if you are a genuinely honest person with integrity, and do NOT like and disagree a specific closing rules, it is perfectly reasonable to:
Follow the "law" and VTC despite disling the law.
Upvote to express your personal approval.
This is what I do with any "Does there exist" or "Any" questions that are otherwise good interesting questions - yes, they are VTCable according to moderator-imposed rules, no, I deeply disagree with those rules despite agreeing to abide by them; and therefore will upvote questions of that type if they are interesting and contribute good content to the Internet which is the main mission of Stack Exchange.
A real life analogy would be a cop arresting someone for violating an unjust law, and giving them a calling card of the best lawyer in town or money for their defense fund.
I say "yes".
I posted thoughts on this on another SE site a short while ago, but they're probably worth repeating in this context, so here we go.
Way I see it, a vote to close is not necessarily always saying "this is a bad question". There are plenty of other reasons to vote to close, and I'm going to home in on one to illustrate this - close as duplicate.
Close as duplicate is not saying "this is a bad question". It's not saying "this is a good question" either; what it's actually saying is "the answer to your question is over here". So close as duplicate is not a slap-down for a question - it's actually the exact opposite; it's a valid way of answering a question.
So given that close reason, is it appropriate to vote up and also vote to close? Hell, yeah. Somebody might ask a damn good question, very well written, but which despite that is answered by a duplicate. They deserve rep for asking a good question. But they also deserve a vote to close for being a duplicate, but a vote to close in that context is not slapping-down the question. It's answering it by saying: "the answer is over here".
The main purposes of question voting are to promote questions that others may find helpful, largely based on how helpful you found it, and to reward people that ask good questions for the site.
If a question is closed, it can't be answered and therefore won't help people. Bigger still, you shouldn't be rewarding people for asking bad questions. Reputation is largely a gauge of how much the community trusts you and shows that you understand how the site works. Asking off-topic questions clearly does not demonstrate that you know how the site works though and hints that you do not understand it that well.
The exception to this would be not-so-obvious duplicates though, where having some variety in wording helps more people find answers that they're looking for. If a duplicate isn't that easily found, shows research effort, and is still a helpful question, then I would probably upvote and vote to close, but not for questions closed for other reasons.