First question is, what's your character's size? A Gnome or Halfling can ride a wolf as a mount, which can help make up for speed. A Medium-sized race would need a Large companion to ride it. I don't know if the Undersized Mount feat is in the CRB or not.
Or you could get something that flies. Give it Fly-By Attack and it can deal damage and just zip back out of melee range.
Keep in mind that without boon companion your animal companion is going to be somewhat weak. While the animal companion will probably be stronger than a normal animal its combat ability may not be up to being a front line combatant. A druid’s animal companion is a lot stronger so they can deal with being a front line combatant better. But even a druid’s companion starts to have problem at higher levels. Druids also have more spells they can use to boost the companion to keep it relevant longer.
A good use for a ranger’s animal companion is to guard another party member instead of being in the frontline. If you have a caster who has no real combat ability outside spells having your animal companion protect him is a good idea.
If you are not using it for a mount you may want to consider a cheetah. Early on they actually are probably better than a wolf. Take weapon finesse for their starting feat and it will have a +7 to hit with three attacks instead of a +3 with a single attack. They also have a much better AC, better reflex saves and only slightly less HP. When they gain the size bonus the situation is different, but then you have to deal with a huge animal.
Because you say your GM prefers role-play over optimized combat, I wanted to say that there are other approaches to choosing an animal companion than attack power. I’m not at all saying that I’m above ACs who can lay down some damage...
If you think you will be in town role-playing quite a bit, you may do well to choose a domesticated animal. They will blend in better than a cheetah, for example. A bird can easily be sent to the skies for safety and can easily zip around during combat to provide a flank. A badger is not a strong choice, but it has climb and burrows speeds and can rage. Kind of fun. A dog can hang out on the street waiting for you, and while it is not as bad ass as a wolf or cheetah, it is a well rounded companion. A dire rat has both a swim and climb speed.
Your AC might have the fewest hit points in the party, so you might consider how well it defends instead of how well it attacks. You could look for something with decent hit points and armor class. If it doesn’t present itself as a threat, the GM will likely attack it less often. In this case, it can provide flanks for the melee combatants in the party.
I’m kind of partial to the elephant, but its not as flashy as some other companions.
I’d actually suggest not taking an animal companion and merely select your party with your hunter’s bond. Nothing like sharing half your favored Enemy bonus with the party for a few rounds.