Regarding OOtS, I never really got into it. If you're gonna even bother with stick figures over plain text, a major raison de etré is using them to give lots of expression, and the ones used in OOtS feel like clip art.
I joined only so I could point out that it's "raison d'être".
Since I'm a member now I might as well add that it's my favourite comic :P
I do prefer the plot. I find that comedy can end up overdone and pushed together because of the need to have a punchline every strip. When you have a plot, you can advance the plot, use suspense and a cliffhanger, and so on, which means you don't have to regularly pull up funny. I also find that it allows you to feel various emotions rather than just "it's funny", which, well, is only one.
I like the story of oots, I like the art style (yes, you heard me, well, read me, right), and I think it was funny enough at the beginning to grab people's attentions (although not mine. The first time I read it I moved along. I oly came back after it had a plot and then I stuck around), and then, has a plot that makes you keep reading.
But I too like some "one gag a day" comics too, such as Calvin and Hobbes or Dilbert. I have to admit though, I always have a feeling of "if only they had a plot..."
Which made me pretty happy that Dilbert became a show, by the way. But I digress :P