Best in what? I'm not sure there is a best all-round pet. Most of them are best at a specific aspect.
highest DPS and burst damage - elite scorps
best CC - yellowstone runabouts
best team tactical support - elite mesh weavers
I use Yellowstones on my Armitage and intend to use Either 1 Yellowstone, 1 Scorpion on my Atrox or 2 Scorpions.
Peregrines aren't bad but Scorpions out class them.
I was once DKnight1000, apparently I had taken my own name so now I'm DKnight0001. If I ask you a question it is not an insult but a genuine attempt to understand why. When I insult you I won't be discreet about it, I will be precise and to the point stupid.