Here is what I like in GURPS disadvantages in my games.
Player-centered. In other words, the player does the work. I'm not a big fan of "once per session the GM will . . . " But I am a big fan of limitations or forced actions on the player. I got rid of Weirdness Magnet in my DF game because it became 15 free points most of the time, because I was too busy to warp the game to make it count. Enemies, Dependents, etc. are kind of a pain.
Clear limits. I like disads that put clear limits on your actions. Sense of Duty means you don't ditch your friends. Bloodlust means you don't say, "I clearly killed him and he doesn't need a finishing blow." Berserk says you can't be a defensive fighter while it's ongoing.
I'm less of a fan of vague limits, which is why I shoot down a lot of player-created codes or Vows or Obsessions. Either it applies, or it doesn't, but if it only applies when it's convenient, it's not limiting your actions and thus not a disadvantage. None of this "Vow: Only do what I want when I want it!" or "Quirk: Always ready for anything!" kind of stuff. It should be painful to read when you write it down on your sheet.
Not crippling. I hate it when PCs have disads that make adventuring just not work, or which take them out utterly. Especially if they have an escape hatch ("I'm addicted to a ridiculously expensive crippling drug, and I'm fine with it, but useless without it!"). I prefer your disads to limit you, not end you as a functioning character at the table.
Frequently appearing. I don't like disads that never come up. "I hate this one tiny group of guys." Great, who cares? Or a Vow of chastity in a game where sex doesn't come up. Or something so big it's effectively a raison d'etre and not a disad ("Obsession: Become the world's most powerful wizard . . . by adventuring!"). It better come up. All of those are valid if they come up almost every session - if you drive the PCs towards the Lost Lab of Alchemy despite the death traps because each session must be a step toward your obsession, great. If you hate the one tiny group of guys who run the area, perfect! If that Vow means you don't get to, uhm, "interrogate" the attractive NPC for special information and fringe benefits, then it's a good thing. Even a perfectly valid disad that can't affect you often isn't really a limitation, so I'm less likely to go for it.
That's pretty much the kind of stuff I like.
And for the love of everything roleplaying, don't tell people you're being X because your character is X. "I'm stubborn because my guy is stubborn!" "I'm being angry because my guy has Bad Temper!" "Don't tell me guy about that treasure, he's got Greedy and he'll want it!" Just play it. We should be able to tell you your disads just from how you play them.