Experimental Fiction

Recently I wrote on a post with some adult book mini-reviews, and it occurred to me that though I had rather opposite reactions for the two books I reviewed, they both had at least some experimental fiction elements (although in the case of House of Leaves, "some" implies a rather... large quantity). This got me thinking on what works in experimental fiction and what doesn't - for me, of course, because I'm sure everyone's opinion will differ on this subject!

In general, I think there are two classes of experimental techniques: one relating to what's written and the other to how it's written. I am a voracious reader of the first and adore short stories of the ilk published in, for instance, elimae, and so I devour books written like this as well. As for the second, I like it to an extent but sometimes it comes across as... gimmicky to me.

For example, Jennifer Egan had an experimental chapter that was written entirely in PowerPoint, and though that sounds weird, it worked and carried across intense emotion to the reader. In contrast, Mark Danielewski's experimental devices were just... confusing to me and made it harder to read (such as having to use a mirror to read passages and frequently turning the book upside down).

What do you think of experimental fiction?