Objective DAC or Modi if you are looking at that price point. Don't bother with soundcards, they have so many noise issues.

+1 on the ODAC at that price point (~$100 bucks). Make sure to buy from somewhere with a return policy though in case you don't have an available USB port that plays well with its power requirements. I've never seen a piece of equipment so variable in its performance based solely on what port you plug it into. 

Wow, thanks for all the suggestions! That gives me lots to think about until my gear arrives. I just came across the doodlebug (http://www.head-fi.org/t/703334/doodlebug-usb-isolator) which looks like it might help if I decide to go the Modi or ODAC route.

The Herus be good shit. I would go with an Audio-GD dac though that would require an optical/coax connection.

If you go the ODAC route, may I suggest the cDAC+ from Audio Poutine as the alternative? It has inbuilt isolation though you will still have to get your own lps.

For laughs, I would also suggest the Stoner Acoustics UD110mk2, supposedly indistinguishable and super cheap. Measures good as well, evaluating it against the ODAC right now. I think it destroys the sub $99 dacs in jitter at least.