A lot of the time there's more awkwardness in saying nice things to people who can't or don't want to hear it, than there is in saying unpleasant things. So, if you feel like playing, post anonymously something nice.
You don't need to identify who you're speaking to/about (but you may if so inclined). It doesn't have to be someone on my friends list, or even someone on livejournal. It doesn't have to be cheerful (but it can be) - bittersweet is okay. Blunt or poetic, also okay.
As ever, anonymous posting is enabled.
Edit, 4/04/2:05 AM: Due to an extraordinarily unpleasant spammer hitting my friends list, anonymous comments are temporarily screened. I doubt anyone is looking at this post at this late date. I will unscreen anonymous comments as soon as I can; I don't like the idea much. In the meantime, I will gladly unscreen any comments made in the spirit of this post. Thank you for your patience. -Corvi