I zone out about three sentences into the bios where they tell you about how they were the youngest of 12 halfling children born to a poor family, yada yada yada.

Bios that I do like to read, and ones that I put on most of my toons, are explanations for things. My rogue Picksie has a bio that states that I let my kids name my toons and my 6 year old daughter picked that one, it isn't a reflection of my orientation, my 6yo daughter is the third of my five children. If you have kids, you will understand. If you don't have kids, you better not be questioning MY orientation

I also sometimes use it as a 'friends' list to remind me who has po'd me recently as I am bad with names, but you have to be a complete tool to get on there.

Or occasionally a SHORT joke about my toon, usually name related. My old cleric Obgynkenobi's bio had some comment about feet in the stirrups, my old rogue Splashlog had a flushing joke in there, that kind of thing. But it better be short. If it starts out with 'A nun, a rabbi, and a priest walk into a bar' then I zone out.