In very general terms, my advice for playing with your pets is the same as it’s always been: use the pets you like the best. I’ve said before that my first 25 was my Perky Pug Bertha. She’s mediocre at best for fighting, but she’s still my favorite pet, and despite her questionable utility I still use her to fight when I can. If you don’t feel any connection to your pets, you’re not going to enjoy playing nearly as much.
That said, I’ve noticed that there are a few pets I use constantly, both in PVP and PVE, and see others recommend (or complain about as being totally OP) as well. That’s the basis of this list. I’m not telling you to level these first. Some of them are pretty bad until higher levels, so I wouldn’t recommend just grabbing 3 of these pets from level 1 and making a run of it. But if the option presents itself, keep these pets in mind. Completely unironically, I’ve done pet profiles on most of these individually, too.
Anubisath Idol – Between the Humanoid racial heal, his big hits and damage avoidance, the Anubisath Idol makes a lot of fights trivial. I’ve seen a few carry guides which include the Anubisath in nearly every Pandaria tamer fight. I resisted it for a while, but come 5.4 you’re going to be glad you have one of these puppies.
Speed Breed Rabbit – I made a whole post on why Rabbits, and specifically Speed Breed Rabbits, are fantastic. They do well in both PVE and PVP, especially with undead teams being in vogue right now, and they’re one of the original pets you could have so they’re super easy to get too.
Crab – Another one that’s easy to get, crabs are fantastic tanks for PVE, and can swap and be damage dealing juggernauts in PVP. Breed is debatable. I prefer the Power breeds, but some tamers like starting out with high Health. It’s up to you and what you’re after… or, because they’re so plentiful in the wild, you can stock up on all of them.
Gilnean Raven – An excellent damage dealer with a lot of tricks up its little birdy sleeve. The Darkness weather ability makes life easy against healers. I also love the underutilized literary reference Nevermore ability. Big damage is nice, but shutting down your opponent’s offense is just sweet.
Clockwork Gnome – A teeny powerhouse with heals, damage over time, and big mech hits. This was one of the very first pets I leveled up, and he’s still a favorite to use.
Terrible Turnip – This is a little bit off the topic, so it doesn’t count toward the 5. The Terrible Turnip is kind of awful. I’ve seen it a few times in PVP as a “wait bait” pet (meaning, they turtle until you get fed up and forfeit, handing them the win). But its utility in trapping pets makes it absolutely crucial to have. I wouldn’t make this your very first 25, but when you get more than 5 you should consider it.