It's embarrassing to admit how long I've spent looking online for single-purpose sound effect sites like Instant Rimshot (first mentioned on Download Squad here), and it turns out that it is very difficult to Google for these things. My goal was to present the top 5 sites that exist simply to feature a single sound effect, but instead you're getting the "top" four. And by "top" I mean "only". Hopefully some of you can post more in the comments.