So, as the thread title says. Vote for either the best or just your personal favourite (because people got butthurt the last time I neglected to make this distinction). I didn't include ED-E or Rex, since they can be stacked with the humanoid perks, but feel free to discuss how their perks synergise with the humanoid ones.

My favourite (perk) is probably Boone's Spotter, it's invaluable and makes long-distance sniping much much easier, especially at night. Veronica's Scribe Assistant is pretty useful too, especially as an energy weapons user (recycling ammo). I've heard many people recommend Whiskey Rose, but since I rarely consume alcohol anyway (unless I'm at the end of a killing spree and need to bump up my carry weight a little) I haven't gotten much mileage out of her perk.

Full Maintenance all the way.

Spotter for me

Regular Maintenance/Old Vaquero. The difference between Reg. Maintenance and Full Maintenance is not that great, and Vaquero Raul with a Brush Gun is a force to be reckoned with.

Whiskey Rose. The CHA Buffs her, The STR helps me put Supersledges in peoples heads, and the DT helps me not die while doing it.

Plus it's pretty badass before a fight to go:

GLUG GLUG GLUG

*Smash Bottle on the ground*

It's Whiskey Time, [censored]es.

Spotter all the way

Full Maintenance. I tend to use rather high-maintenance weapons such as Tesla Cannons, which this helps with. Raul is just as dangerous with Remnants PA, the CZ57 and a small mountain of Surplus rounds.

-Nukeknockout

Ed-E's Enhanced Sensors and Camarader-E (just the first rank is fine, all the rest are just icing on the cake) are my favorite companion perks, but since I have to choose a humanoid I chose Spotter, since it's fairly useful and synergizes very well with Enhanced Sensors.

Spotter. It's practical and there is no other way to get its effects.

Since I couldn't choose both of Cass' perks on this poll I chose Spotter.

Spotter is fantastic during nighttime, however I still prefer Whiskey Rose in the long run, as it is very handy for someone sticking to light armor.
Raul's perk is pretty redundant, since there is always a million tons of stuff to keep your equipment in shape. and I'm saying this as someone who always chooses the Built to destroy trait.
The best perk for me is ED-E's enhanced sensors. Knowing about the enemies presence before they detect you is invaluable