Hi S&G,
We stayed in the Wentzl Hotel, right on the square. It's currently Number 2 in Tripadvisor top list. It's a 4*, but we got a good deal through one of the hotel booking sites (not sure which now). Bonerowski Palace Hotel is on the opposite side of the square, also 4*, was our original choice but wasn't available for one of the nights we stayed. Both of these are small, boutique hotels rather than chain types and I can recommend both. Plenty of choice though at all price ranges.
If on a budget and staying a few days, consider staying in an appartment. Plenty of these in the guidebook I linked above. Some are also mentioned in Tripadvisor.
Caveat is obviously not thinking of applying for a job in the Polish Tourist Office in the near future....
"Depressing, bleak and soulless together with mostly awful food and a population seemingly entirely unfamiliar with tourism and service."
Our experience was the direct opposite in each category he mentions.