Using liquid oxygen (which is "naturally" extremely cold) is the standard for almost all professional civilian launchers. There are some odd exceptions - launchers like Lambda 4S using solid propellant. A lot of systems use RP-1 or other non-cryogenic fuels, but for oxidizer in commercial, planned, civilian launch systems that were developer as civilian since moment one, LOX is the king.
("Small" civilian rocketry - amateur, sounding rockets etc often utilize nitrous oxide $N_2 O$ for oxidizer - but it's a gas at STP too)
The situation is quite different with the military. The rockets either use solid propellant, or hypergolic fuels which aren't especially cooled. This also applies to civilian launchers that are derived from military - like Proton (as mentioned by Organic Marble) which was designed as a super-heavy ICBM launcher, or Start-1 which is a modified mobile ICBM launcher repurposed for civilian use.
The reason is fairly simple: boil-off. Rocket's LOX tanks aren't made to withstand high pressures - the liquid oxygen slowly boils off. It means the rocket needs to be fueled several hours before the launch. This takes time - which is not something the military systems can afford. The rockets need to be ready to launch at moment's notice and sit in the launch silo, fueled, for months or years. This requires propellants that don't boil in room temperature.
By the way: what SpaceX does is additional cooling way below boil-off or ambient temperature. Such propellants in fact have worse performance per mole or kilogram of propellant - but decrease of temperature decreases volume - increases density; you're getting a better performance out of liter of the propellant - essentially you can fit more propellant into the same volume of a rocket tank.