If #BIOS vendors could standardize on one key to get a boot menu, and give me enough time to see on the screen which key that is and press it, that'd be great.
Back in the #retrocomputing days, this wasn't a problem because computers did a lengthy memory test at power on, but that's long gone now. Also, the screen came to life right away, whereas now the computer is already most of the way through the POST sequence when it gets around to initializing video.