Bebop Pedals/VP Components
entry price: $90 for pair (Chromo)
Rep. Cleats: $35
Availability: US, relatively easy to get. Outside of US, not available.
Float type: 20° claimed float, unrestricted (±10°? Can someone tell me this, I don't know.)
Quality: super quality, simple to use and maintain, great ratings/reviewsd from people who've tried them

Crank Brothers [Egg beater, Candy, mallets]
entry price: $50 for pair (Egg beater C, Candy C)
Rep. Cleats: $20
Availability: easy to get.
Float type: ±5° float, unrestricted for first 5°, Spring self centering after 5° (unsure, couldn't pull up data)
Quality: crankbros VERY poor reputation with both mechanics and LBS assistants - been warned off so many times it's not funny

Shimano SPD
entry price: $40 for pair (SPD-M520, etc.)
Rep. Cleats: $10
Availability: easily the most carried.
Float type: ±4° float, spring self centering
Quality: Get them and forget them, they last forever. Until they break, that is, and fixed toe so not true float.

Speedplay Frog
entry price: $105 for pair (Chromo, MSRP)
Rep. Cleats: $35
Availability: Relatively available, just find a speedplay seller.
Float type: +26° float, unrestricted, one direction (BEWARE! Cleat only allows Heal out float!)
Quality: Pedals are decent, but the cleat binding mechanism uses an elastomer instead of steel. Pedal requires regular maintenance.

Time ATAC
entry price: $50 for pair (ATAC Alium)
Rep. Cleats: $20
Availability: Easier to get than bebop pedals.
Float type: 10° FREE float, ±5°
Quality: bombproof quality, very easy to rebuild, the couriers' favorite pedal