I only use the pool if its outdoor and in a resort type hotel where I’m having a few days off.
For me the most important is free wireless internet. I’m using iPhone/pad and a Samsung Galaxy phone, so it annoys me no end if I have to pay for two or three connections.
Next up is a decent room-service menu, especially when staying alone. Food should also arrive hot rather than lukewarm.
Finally, TV that includes BBC, Sky and CNBC, and if in Europe, then a few other English channels as well. Seems to me most hotels provide amply for the Germans and Arabs but not so much for Anglophones!