I used to be a CRJ200/700/900 guy. Used a classic David Clark for a while, then switched to the Lightspeed Mach 1 In-Ear headset. I will never use a different headset. Hands-down the lightest and most comfortable on the market. The customized ear-pieces become very comfortable after about a week of solid usage. You can change which ear you want to the mic boom to be attached to. If you have a jumpseater on board, you can remove one ear piece, not miss a radio call and still have a perfectly audible conversation. Plus, it comes with a modulator allowing you to use the headset as an earpiece for your cell phone. Additionally, for what it's worth and I never tried it because I don't believe in listening to music in the flight deck, you can plug your iPod into it and the radio calls will intermix over the music.
Only downside is that it's rather pricey $ $ $, but worth the investment IMHO. I traded my 4-year old DC's (used and abused since I started my flight training) to Pilotshop (pilotshop.com) here in PHX and got 160 for them.