For really bargain basement you could probably pick up an EMU0404 usb for around $150. I'm not sure if it's truly balanced or using some opamp shenanigans.
I am interested in measurements of the ESP950 on the KGSS vs E90. To see if there is a measurable difference. Don't worry I'm not doubting the KGSS sounds much better
Usually what I reach for these days; good dynamics, fairly complex. But a lot of times it's just what I'm in the mood for. On the demo CDR I made it is a combination of symphonies, harp bop, industrial, classic rock, acoustic and folk music.