is there any audio player that works similar to winamp? so it can play
- most importantly files from within a folder (whole folder or one file)
Any HTC Android phone should have two music players by default, Android's and the one made by HTC. Both should be able to do what you want. If you don't like them there are at least 4 or 5 others you can download from the marketplace that should have the features that you like. A few popular ones are MixZing and Meridian.
As Webs said, there are any number of decent Android audio players out there.
The one I use is MixZing -- however, streaming support is not yet supported, and still listed as "And even better to come..."