No real "go-to" for me - it all depends on the task.
Given that, there are some ratchets I end up using more than others:
1/4 Drive: Kobalt Ergo-Handled 72 Tooth. Husky (Gearwrench) Roto Ratchet
3/8 Drive: Snap On F80, Carlyle 100 Tooth Roto Ratchet
Don't use 1/2 Drive much, but when I do an old raised panel Craftsman works for most of those tasks, and it's a beat up and cheap enough tool that I don't mind cheater barring it if needed.
I am a HUGE fan of roto-head ratchets, thought they looked goofy and gimmicky when I first saw them, but actually using them made me a believer!
If I could have only ONE ratchet out of all my tools, as a "do everything" tool, I would choose (with VERY little hesitation) the Snap On F80 - that thing is as close to a perfect "do everything" ratchet as has ever been conveived - at least for the kinds of work I do. Why not the Roto Ratchet for this? Easy... there are times you REALLY don't want the head to flex, plus the roto head does not fit in some of the tight spaces the F80 pear head will. Plus, there are always universal sockets and extensions for times where flex is required... works most of the time if you don't have a flex head ratchet.
This is the Kobalt ergo-handled 1/4 Drive ratchet I'm talking about: