Which Familiar is the best?

Which familiar is the best? Sorry if a similar thread already exists
source (ToB familiar stats included on this page) - http://www.pocketplane.net/volothamp/familiar.htm

Pseudo Dragon- Lawful Good, Neutral Good
24 hp, AC=-2, THAC0=13, ApR=2, 1D3 Piercing+chance of Sleep. 50% Magic Resistance. Can cast Blur 1x/day. Regenerates 1hp/round.

Ferret - Lawful Neutral
24 hp, AC=0, THAC0=17, ApR=2, 1D3 Slashing. 50% magic resistance, 75% Pick Pockets, 20% Find Traps, 40% Stealth.

Imp - Lawful Evil
18 hp, AC=2, THAC0=19, ApR=1, 1D6 Piercing+chance of Poison (POISON = NERFED IN BG:EE, DOES NO DAMAGE). Resistances: 25% Magic, 100% Cold/Electricity/Fire. Can cast Polymorph Other 1x/day. Regenerates 1hp/round.

Rabbit - True Neutral
24 hp, AC=1, THAC0=17, ApR=2, 1D2 Slashing. Resistances: 65% Magic, 75% Cold/Fire/Electricity. 30% Stealth, 50% Find Traps.

Dust Mephit - Neutral Evil
24 hp, AC=6, THAC0=17, ApR=2, 1D2+1 Slashing. Resistances: 10% Magic, 50% Slashing/Piercing/Missile, 100% Fire. Can cast Glitterdust 1x/day & Glass Dust 2x/day. Regenerates 1hp/round.

Fairy Dragon - Chaotic Good
24 hp, AC=4, THAC0=17, ApR=2, 1D2 Slashing. 32% Magic Resistance. Can cast Mirror Image and Invisibility 10' Radius, each 1x/day.

Cat - Chaotic Neutral
24 hp, AC=0, THAC0=17, ApR=2, 1D3 Slashing. 50% magic resistance, 30% Pick Pockets, 99% Stealth.

Quasit - Chaotic Evil
24 hp, AC=2, THAC0=17, ApR=3, 1D6 Slashing. Resistances: 25% Magic, 100% Cold/Electricity/Fire. Can cast Blur & Horror each 1x/day. Regenerates 1hp/round.