Slot #1: Hati (Spirit Beast). For any kind of group content (M+ / Raids).
This one can differ a bit; mostly it's the black Hati skin, sometimes I take out Gara (the purple wolf) and sometimes Loque.
Slot #2: Soundless (Ray). This is also for groups, in case I need to bloodlust, but want to keep the dispel. I don't use it that often, IMO Drums + Spirit Beast > Ferocity pet.
Slot #3: Brown Clefthoof. This is for harder solo content. With 15% leech, 10% more armor, 20% more healing taken (from both the leech and mend pet) and the massive 60% DR this pet has there is little it cannot tank.
Sometimes I'll swap this with a Corehound, depends a bit on the situation. The 50% DR from Corehounds (and Scalehides) is much better, as it's half the cooldown and doesn't trigger passively and the damage reflect is quite good now. But I feel like the 20% extra healing and 10% extra armor are quite a bit better survivability wise.
Slot #3: As above, sometimes Corehound. I quite like the Omen model (2 headed white dog).
Slot #4: Snowfeather raptor (Raptor). This is my Survival pet that I use when questing or pvping as survival. (IMO survival is a bit better for casual world questing and definitely for pvp).
Slot #5: Mostly empty in case I feel like taming something.
I've thought about equiping a Silithid here for general questing as BM. I feel like the cunning movement speed and silithis +30% movement speed are the only things that would be useful in regular content. But I find I'm mostly using the spirit beast or raptor if i want the speed or questing as Survival (with the raptor); so for now it's an empty slot