my all time favorite is Xufu. he's a monster on so many levels. he does great on healer/stall teams, sunflower and crawdad, because of his prowl > feed combo. if u want a powerhouse one shot that PoS crow, prowl > moonfire. after that, his main attack with no cd hits for 500+ and always lands...ALWAYS (looking at you death adder
) on top of all that, he's a big, gorgeous, freakin' BLUE tiger...who DOESN'T want a blue tiger?
Anubisath Idol is a very powerful pet, for both pvp and pve as he can give u free pet swaps on a lot of the npc tamers for lowbie pet leveling. he also looks pretty neat and has just a ton of variety for his moves. the humanoid self heal, broken mechanical damage, flying damage/mitigation, elemental damage/maybe stun...it's just not fair sometimes lol
one of my oldest pets, and probably my most summoned pet is Lil' Ragnaros. he's ridiculous in pvp battles, not so great in pve. he has a very consistent random combo that seems to really foil anything but a critter. when that trap goes off and u "hulk SMASH" their face...it almost makes me feel bad lol almost
and of course those being my current favorite pets, they are my main pvp team right now. they have no real synergy but they are all highly consistent power hitters and few teams can stand up to them, even valk/adder, they can't be heal stalled, and even when u completely counter the whole team you'll probably only barely beat them. in fact, the only thing that seems to really beat them is that RNG love