To be honest, the pet most hunters run around with at 70 is either a cat or a Lightning Serpent. The former is the premier DPS pet in the Burning Crusade, while the latter is the Raid Hunter's choice for maximum pew - although you need to know macros to get it to work properly.
Ravagers (what Baud means by "reavers") are good DPSers, too, but they are uglier and lack the flexibility a cat does. Same Damage output, the Ravager has more armour, but whereas the Cat has a -2% Health modifier, the Ravager has -7% - trust me, that counts.
Ofc, given your current level, and the changes in WotLK coming, I'd recommend either a Cat, or a Wolf, which will switch to being a premier DPS pet (yes, I AM grinning manically, those who know me) - at Level 31, nip to Ashenvale and grab a Wolf from near Astranaar, maybe more to the east - some good 27s near there, and the level differnece will enable you to equalise it fast. Wolves won't do the damage of a Cat, but they have better Health and Armor, and Furious Howl is one of the most under-estimated party skills going.
Oh yes, and while I remember, Boars are a waste of time - 10% LESS Dps than basic non-dps pet families, 20% less than a Cat or Ravager, people take them for the charge, but it's a one-trick pony. I wouldn't touch one with a barge pole.
And before I forget..!
Raptors - some low level critters in Barrens, accessible from Ratchet - if neither a Cat nor a Ravager appeals, get one of these - same DPS, and a happy medium between Cat and Ravager Armour/Health.
Hope that's helpful.
