whenever I do find people who rage over losing in their nametag, all I change mne to are either, "waste of my time" "getrekt" "keep practicing kid"
I don't ever change mine unless my opponent does first, and I only do so when they try to start attacking me with their nametags first after they lose. most of the time i change my tag to GGsGTG, or just GGs if my opponent doesn't try to rage with their nametag.
I don't often find that many who get that salty anymore though when they lose, most of the time they just quickly quit or put me on block at the results screen and then leave if I really beat them hard in the match.
What I find more, and is sadly more annoyng and why i wish they'd make it so you can't change your nametag in the wii U version...are the arrogant assholes who after a win start gloating about it the whole time with insults in their name. You beat me in a match, gratz, no need to be a **** about it.