Your favorite rear end/final drive ratio and why?

I have a rr with a factory 4.10 dana and a 727. I didn't consider a 3.54 swap, cause I didn't think the difference was worth the cost. Now that 3.23s are available, I'm reconsidering. (I lprobably won't, it's a real A12)
I've got a primarily bracket car that gets street driven occasionally, with 3.91s. Perfect for this car. Has had 4.11 and 4.56s in it, runs exactly the same with 3.91 so why beat it up with too much gear?
I have 3.50s in a big block powered Opel, but that may change. (Nine inch)
Next project is a 511 in a notch barracuda. 3.23s will be the choice there, It won't need any gear to run good. I'd run 2.94s if I could find new gears, pretty sure they don't exist (maybe oem dealer? I don't know).