AMP (tyco) is the biggest probably. their quick connect line is called "faston".
You can get them from the usual electronics suppliers, digikey, mouser, newark. I feel like mouser has the best selection of automotive connectors (housings, etc, not just terminals), but newark is usually better on price.
You're thinking of these, yeah?
Mouser has a lot of the amp junior timer housings (mostly german cars use that), but they also carry some delphi stuff for GM.
I don't know what environment your vehicles will be in but if it gets salty I'd recommend using sealed connectors. The terminals inside are the same idea, but the housings are all sealed. (same crimper would work for these).
junior timer, old german connector, sealed or not
modern sealed german style, uses same contacts as above
Then here's a few deplhi ones, probably recognize these from GM cars
"weatherpack"
"metripack" - come in 3 terminal variants for current capability, 6.3mm, 2.8mm, and some tiny one. Roughly american take on german standard/junior/micro timer series.
Deutsch "DT" and clones are very common in industry
and there are 1000 japanese ones on top of that.
Anyway I guess point is a good open barrel crimper will crimp any of those. (the ratcheting type that crimp the wire and insulation in one stroke won't though, as they're more tailored).
Edit: I have a bunch of ratcheting crimpers which work great for a specific 1 or 2 terminals with 1 or 2 wire sizes, but outside of that they are very restrictive. Cheapo non ratcheting ones where you can pick both dies for the crimp and insulation are more versatile in that regard.
I usually use Molex one like this. $40 or 50 I think.