What do you think are the bushings with the "snappiest" rebound/ return to center
Without getting too deep into specific bushing brands, duro options or a lot more, the two main things with bushings that allow for that very quick return to center is breaking them in gently and not doing them up too tightly, so they can do what they are supposed to do.
Brand new bushings for the most part will need a bit of time to get them going nicely, but also having the best tightness on them will also help with everything in the way they perform too - tightened down too much and they aren't allowed to perform to their maximum capacity, or left too loose and they will wobble and not be stable, even with the hardest bushings on the market.
I know some people will always say having the kingpin nut flush is the best position, but I could also say that for a good number of bushings I have on the go, having them down a thread or more also works just fine and I usually take the kingpins down to match easily enough with an angle grinder so everything fits just right.
Now as to which bushings will work best, I have had a lot of brands of both stock and aftermarket, not limited to Indy, Thunder, Venture, Ace, Slappy, then Bones bushings and other specific brands sold separately, but would say quite often that the bushings of 90, 95, 100 or other duro options can all be made to work well, or can all also have issues, depending on the user, the trucks, the washers, etc.
If you prefer harder bushings, or tighter trucks, it might narrow the field considerably, but even some of the harder options out there can still end up quite loose feeling as they break in and compress, so for some I have seen, in no way can they be so tight that there would be very little movement in the trucks and still have a good rebound on them.
For some people, it almost seems like the tighter the trucks, the more issues people have with them, but I think with a bit of time and patience, almost any bushing brand can be made to work well under the right circumstances. Some people change bushings out every other week, or month, or even shorter times, if things are not working how they are supposed to, but I think these people often don't put in the time to break in bushings that well either.
* That might be way too long, without actually helping at all, so I am sorry there, but I guess if you have bought a good number of bushings and have been working through them, a bit of time is the main thing to get them worn in nicely, after which they should have a bit more rebound and do as needed.