I usually use a random name I'll either reuse or borrow from characters of mine that never see the light of day (which are usually names I've made up). They're not supposed to be the characters they're named after by any means, but I just need a name to use, and I tend to mix them up periodically.
In less serious playthroughs, I may use memey names, though, which are more than likely to be based on characters in media or another source of my meme culture.