I used HDDLoader then switched to Complex Tools. Complex tools looks cool, and it lets you Listen to your music while the disc is copying. You can also delete games, launch games, and do some other things I haven't tried like extracting xbox iso's from the the HDD.
The only problem with complex is that you have to go into the ini file if you want to tell it to patch xbe's. I had to change the setting so that it would apply a patch to Ninja Gaiden. The whole reason I tried it out in the first place was because Hddloader doesn't patch (to my knowledge), and NG needed a patch. So then I thought I could just leave the patching setting on so it automatically patches all my games, but unfortunately some games don't work if complex tools patches them. (Namely Wolfenstein and Deus Ex). So it's a slight pain to have to reFTP the ini file over so that it knows to patch or not to patch (But i'm guessing 80% of games will copy correctly either way). A simply menu setting to turn patching on/off would have been a nice addition to this app.
I also have dvd2xbox but haven't used it. Since everyone thinks its so good, I'll have to try it. Can't play music in dvd2xbox though can you?