What class amp is the best?

Hey there, I'm looking to upgrade my audio system and I'm wondering, what class amp would be the best choice for me? I've heard of Class A, Class AB, Class B, Class C, Class D, and Class G amps, but I'm not sure which one is the most efficient, produces the best sound quality, and fits my budget. Can you help me navigate through the options and give me some recommendations based on my needs? Thanks in advance!