I use the Voxengo Tube Amp plug on damn near every single project...
I find it invaluable for some rather unusual uses...it brings accoustic instruments to life, warms vocals quite nicely, even works well on drums..or entire mixes!!!
I freekin' love this plugin, and i know you will too... you can hearit at use here:
http://www.songplanet.com/jimipocius on virtually every single song!!!
You won't find a better sounding tube style plugin anywhere at any price...
thanks to Voxengo for keeping it real, and making it FREE!!!