Choose best sub

All right I almost don't know anything about car audio so can you guys pick the best sounding/biggest bass subwoofer.

Alpine - Type-R 12"
Infinity - Kappa Series 12"
Polk Audio - MOMO 12"
Viper - V4 12"
Performance Teknique - ICBM-5912 12"
Xtant - X124 12"
Kicker - Solo-Baric L7 12"
Audiobahn Flame - Q Series 12"

I think this question had been posted maybe 3,000 times...do a search and you will find them. Its all about personal preference. There are higher quality subs than what you posted, such as Elemental Designs, Adire, Resonant Engineering, etc. Just do some research and buy the brand that seems to be fit for your needs.

Out of those posted, the kicker is probably the best sound.

I'd say the kicker would get the loudest, but it's far from having the best SQ out of the bunch. Like chicago_guy said, it's all about preference.

what will the best amp(s) i will need for 3 12" L7's?

first off, how much space do you have per sub? secondly, how much are you going to spend?

you will need an amp that will put out acurate power, and not sound crappy, so like avionixx or dei or... just do a damn search

its for a 2000 Yukon XL i dont know how much space it is in feet or anything but i think it has enough space. And less than $2000

$2000 for the whole system?

2000 for subs and speakers and a decent headunit, I could do it. I would go with a e15a.22 ported, a tsunami 1100d amp, 2 good front stage components. a 2 x 100 or more good amplifier and a Pioneer headunit. You would be set.