Winamp is an excellent player and there is a great deal you can do with it in terms of configurations,I/O plugins and overall looks. I think to get the best possible sound out of it though, you need to do some work. I don't use it that much anymore, mainly because of the way it handles files and albums.
I lean more towards Foobar and even more towards Album player these days.
There is enough configuration and quality output plugins ala' ASIO, WASAPI,KS...etc that you should be able to get excellent bit perfect sound quality out of it easily.