I looked and didn't see anything too similar to this so here we are.
I think the topic heading is pretty self explanatory, no format required, just chewing the rag on personal preferences. My selections to follow are typical to me since most of my builds involve either some audio component or some motorized component, as my prior experience with electronics that really brought me to Arduino was in stereos (I like to party) and hobby grade RC stuff (again, I like to party!)
For audio, I prefer premade, inexpensive class D/T amplifiers and the Adafruit Wave Shield.
Reason for the Wave Shield: it was the first one I tried to play .wav files for Arduino projects, and worked well enough that I bought it a few more times since it was good. I may look to the DFPlayer in the future and use .mp3 files, if I can't find the now aging Wave Shield or don't wish to be tied to an Uno.
Reason for the class D/T amps by companies such as Kinter or Fosi Audio, they are cheap as chips for what you get, if you decide to break down your build later on, you still have a nice little shop amp and a lot have BT built in. Also very easy to power, no doubt anyone reading this thread already has a suitable power supply in their wall wart dust bin (you DO all have a wall wart dust bin, I presume?).
For fixed installation audio, prior to the amps I just mentioned, I preferred going to the local charity shop and picking up a car audio amplifier. Works great since I have a collection of 80s and 90s era stereo speakers that neighbours have put to the side of the road over the years I have hoarded that I just wire the amp to. This is a goto route for me if I am using Arduino and Processing together, such as in my laser maze.
I avoid the Adafruit amplifier modules. I have tried I think all of them up to about their 2020 or so catalogue, they...work...but I struggle to get crisp output from these when used at maximum volume, which it has to be for the type of things I build.
I also avoid LM386 type amplifiers. Far too wimpy for anything I would be building.
For motors, I again use commercially made solutions and interface those with Arduino. I don't use starter kit type motor drivers such as the popular ones seen in the forum which I think are the ones that come with that Elegoo starter kit of debatable repute.
Thus, I avoid the L298N. While I'm sure they are fine for many applications, especially inexpensive school-type robotics, I don't build that scale so not the right solution for me.
I also avoid Pololu drivers after two bad experiences, namely Wild Thumper and T Rex models.
I had I think circa 2015 or 2016 catalogue year models, and after spending the bucks for the former (with shipping and duty), it lasted all of three seconds trying to drive two 12V DC brushed gearmotors driving a maybe 15-20 pound max at the time, differential drive robot before one of the MOSFETS literally exploded. Then I tried the T Rex motor driver and it did well until it started overheating and going into shutdown mode (iirc) once that same 15-20 pound build grew a little larger and was being used for for than ten minutes at a time.
So now I prefer Dimension Engineering Sabertooth 2x60. I have an unused 2x25 driver which works the same way, has lots of options and very good documentation but both robots I used the 2x60 in have never had a single issue. One was the bot I mentioned before, I think it was about 50 pounds unloaded, but was an easy 60 with "tabletop" style payload and still pulling a garden cart with 100 pounds payload, tested.
The second 2x60 in still currently installed in my second "robot" (RC control, I've never got into making these autonomous for safety reasons), which I have never weighed but estimate at something like 200 pounds. Again, no issues, never even goes into auto shutdown and i like to take it for walks around my very hilly neighbourhood.