Male alien "hair", both original and mesh conversions. "Hair" in quotes, because I'm thinking of... things like the Darth Fubar Twilek lekku and that Togruta montrail mesh, and so on, which aren't technically hair but are classified as hair and essentially hair for all intents and purposes. There's a decent variety of women's alien "hair" to go around out there, enough you could default replace like crazy (I keep meaning to do this), but pretty much a male Sim has to either make do with hair-hair, wear a hat, or go bald.

There is never enough not-sexy underwear or exercise clothes for any gender or age.

Those who fix borked meshes and animation bugs are like unto the gods. And also awesome.