Another interesting video re ratcheting wrenches. The main point is don't buy expensive sets, only the sizes you need.
I don't really like the idea of having tools I don't need and won't use, but I have to say I don't agree with the "don't buy sets, just buy what you need" credo. The reasons why are (A) often you don't know what will pop up that you didn't anticipate and (B) when that happens it can be a major frustrator and momentum-stopper.
Today I was doing the cap and rotor on my old BMW. Because I have a custom radiator that is thicker than stock, it was a pain in the ***. I felt better (and pissed off) when I found that the two two harder bolts to access weren't very tight at all. The thickness made it hard to get a tool on them, and the fan shroud really cramped the space too. I really needed some stubby, thin-walled 8mm sockets, but on one of them I wound up using my 8mm 3/8" SK socket and a stubby ratchet, which was shorter than my SO 1/4" roto and my 8mm 1/4" sockets (from Tekton and SK). On the hardest one, my Icon 8mm long flex-head was the only thing I could figure out. The 'easiest' one was OK with the SO 1/4" flex and the SK 8mm socket (while still pressing on the fan shroud).
For various related or semi-related things, I also used my SK X-frames, a regular Tekton wrench, an old Gearwrench 10mm ratcheting flex head, my 4140 pry tool, and a few other tools. All of them kept me going. I felt really grateful at the end that I've accumulated the right set(s) of tools to allow me to gracefully get through doing the job and doing it better than whoever did the cap/rotor the last time (it's been a few years, so I'm not going to go back in the records and look). If I'd had to step away to go buy a new tool, I would have been (A) pissed and (B) delayed multiple days with a dead car.
Net: if you don't get carried way, having a good selection of tools makes things better. I know there aren't many folks here who will argue with that...