Positive GMPC experiences?

[Duff]

My first BECMI campaign we shared the DMing. I remember no issues with people favoring their own character. A few games since where GMing moved around without issues re the GM's character

A Changeling game where the GM ran a character who was, by any normal interpretation a GMpc. The GM often hit "her" character first if we got ambushed which meant if anyone went down and missed the rest of the fight it was probably the GMPC - so that was good. She joined the character interactions a bit but wasn't a particularly dominant character.

The bare minimum for an okay DMPC is not stealing the spotlight. A great DMPC is also able to contribute to problem-solving in unintrusive ways without stepping on other characters' toes, and is an interesting (or, let's face it, probably mostly just funny) character in their own right.

Works. I like to sometimes have my NPCs/GMPCs to ask the dumb question that moves the conversation along. When the party needs to get up a cliff and their plan starts at the top of a cliff and goes from there "How do we get up the cliff?"

So I think visually DMPCs look like PCs. An NPC might be a knight, but a DMNPC is a Knight riding a totally sick werewolf that is her transformed boyfriend wielding a lance of light. The wizard that accompanies them to explain lore is an NPC, but Gerald Hearthsaver of the Million Spelltattoes is probably a DMNPC. In other words, PCs look like derpy super heroes almost every time and NPCs look like they fit in to the setting.

Wait, your PCs look like That???!!!