If you've spent any time around pro audio gear, microphones, consoles, active monitors, you know all about XLRs. They work, they are rugged, and they are a pain in the arse to solder. There's no magic though, it's just a bit of wire with some plugs on the end. There are also 5 pin XLRs, not very often seen in audio, which get used for DMX stuff, and 7 pin XLRs, which some valve mics use, when they have an on-board valve, and/or an external box to mix multiple capsules.
The other option which gets used in pro-audio which hasn't been mentioned for balanced connections are bantams and 1/4 inch jacks. These tend to get used in situations where there's likely to be lots of plugging/unplugging, so patch boards and inserts on consoles, but the lack of a latch stops them getting used where it would be embarrassing for them to get pulled out mid set. Both would be pretty good for home audio.