Samsung CaptivateI use the standard Music App, although I have purchased Mixzing which is also awesome.
Android 2.1
First, THANKS for mentioning MixZing. It does EXACTLY what I needed - recognize playlists - OR - builds them on the fly. I have MP3s in folders on the SD card.
For anyone else - I too just dragged the folders with M3U playlists onto the SD card (into a folder I created called /Music). Let's not get into how much I hate itoons. MixZing found them without any help from me.
I DO see two playlist names in the list of playlists. Not sure why. I've found the first is empty - won't play. It's always the second so that works.
I could not believe with all the Androids and Android users there was not something like MixZing out there. Had to find mention of it here. Saw it in the market but the reviews there did not convince me it is what it is.
The Captivate is only days old so watching the battery with a widget on the home screen to make it easy to monitor.