Well, as I’m in the U.K. and work on a lot of stuff that uses them, I’ve got a load!
Most of my wrenches are older British made ones, mostly Britool, but some Bedford, Gordon and Garrington too. I have fairly complete sets of open ender’s, ring spanners (box end if you live in the U.S.) and combination wrenches.
I also have a nice set of Snap On combination wrenches which I tend to reserve for aircraft applications!
Socket wise, again it’s mostly older British makes, primarily Britool, but I do have some more modern KoKen (very nice quality, and one of the few makers to offer a good selection of sockets in Whit / BSF, including 6 and 12 point, deep and universal). I also have, again, Snap On sockets in both 1/4 and 3/8 drive for aircraft applications.
Much advice here is good. Yes, BSW and BSF use the same range of sizes (BSF fasteners are one size smaller) but only on pre war equipment! After that both BSF and BSW use the same (smaller size), and 3/16 and 1/8 use BA sizes!
Personally, I would avoid using ‘something close’ and get the correct tools. I knew a guy who was restoring an old fire engine. He was using a metric socket set and wrenches and just picking the nearest, but of course if a metric size doesn’t quite fit, you end up using a size nearly a whole millimeter bigger, which is too big! Every nut he attacked seemed to be rounded off!
When you have the correct tools life gets easy - measure the thread, pick up the wrench so marked - easy. You will only need about 4 sizes for a bike, and probably only one more on a car!
Good advice to get some BA sizes as well. When the U.K. adopted Unified threads (SAE) the smaller numbered threads were not generally adopted, so BA sizes were used much later. 2, 4, and 6 will probably do most things!
If you’re looking to buy new, I’d probably go for King **** or Elora wrenches. There are many others, but these are probably the best quality for the price. Snap On are very nice but very costly! For socket wrenches it pretty much has to be KoKen, though the King **** are pretty good too, and certainly rugged!
There are a lot of British Standard sizes out there. Although I use them on vehicles, and even aircraft parts, I use them most on machine tools. I’d say the majority of machines I work on use BS fasteners. Even relatively new machines have them. The biggest single use, worldwide, is probably pipe threads, and you find these everywhere - except of course the U.S.