Now that you've ditched the mp3s, you need to start using a better sounding music player on your computer.
I know WinAmp has millions of acolytes, but if you really want a good sounding musical experience (which you obviously do, or you wouldn't have joined the ranks of FLAC monkeys) go with
Foobar. It may not be as fancy to look at as WinAmp or WMP, but its equalizer is way more powerful and the sound quality is disgustingly better. (Plus, it plays EVERY type of music file under the sun natively.)
Give it a shot. After using it for awhile, WinAmp and WMP will be anathema because the sound is so much crisper in Foobar.