There are plenty of sites that will critique or flat out make fun of "bad" RSPs, but they tend to get nasty, elitist, and judgmental. Sometimes they spotlight good RSPs and give advice on ways to write a RSP or how to improve a "bad" RSP.

RPers' Lament could do this, when they weren't trying to craft jokes about the writing. They tried to never attack the writers themselves--an important part of critique some people can't separate, that a criticism of one's writing does NOT equal an attack on oneself as a person or even a writer--but there were times when some grudge matches were obviously occurring, despite claims. The "here's how this might be improved" often felt tacked on. But they never claimed it was anything but their personal opinions and subjective, and they did attempt to help some newer folks and spotlighted decent RSPs, and offered helpful advice at times. Those parts of the site are worth reading at least. They aren't really doing much with WoW lately, though.

Sites that actually collect good RSPs, or offer advice, are few and far between. I recall Lament even noted how much more traffic they got compared to those "Good Guy" sites (as people liked the ~drama~ that could occur). Checking server forums for the RP character threads, looking for their server wikis or story sites, might point to where peoples' RSPs are, or at least their character info in long form. RP Haven once had a "Show your RSP!" thread, years ago; I may dig it up and revise my own entries to it.

@LynMars

Thanks a lot, these are very helpful sites, just what I was looking for.

Back when I was a member in an RP guild, we used to put these stories on our guild site where we could discuss them and point our fingers on lore mistakes and stuff, in a very friendly and constructive manner of course. These 'tested and approved' backstories couldn't be seen by non-members, though. In our RP guild, we generally left those stories out of our RSP flags because it just caused a lot problems with external roleplayers who couldn't (or didn't want to) separate between IC and OOC knowledge. So, the less they knew, the better the roleplay got.