?? (PC, non-thunderbolt)

How many inputs do you need?

4 tops, what I'd REALLY like in an interface is the ability to A/B speakers.  So at least 4 analogue outputs.

http://www.sweetwater.com/store/detail/Scarlett2i4This is a popular one on the lower end.
 
Something like a MOTU UltraLite-mk3 Hybrid could work. It's $50 more and I can't vouch for MOTU but a lot of guys here use their stuff. It does have more than 4 outputs though.
http://www.sweetwater.com.tore/detail/UltraLite3Hy

Steinberg UR44. 6 in, 6 out, 2 headphone mix outs. It does have multiple speaker outs but there's no A/B switch.
 
I've tried Roland and Focusrite interfaces in the same price range and this is my favourite.

What about the babyface pro?

I have the Audient iD22, and although it's just north of $500, it has 2 sets of outputs, plus a great sounding headphone output, that can double as a third output. It's got 2 mic inputs with phantom power, phase reverse, bass rolloff, and -10 DB attenuation on each channel. Channel 2 also has a great sounding DI. There are customizable buttons for talkback, mute, dim, etc. Might be worth a look.

Edit- I forgot to mention that it is also a great sounding monitor controller.

TerraSin
http://www.sweetwater.com/store/detail/Scarlett2i4This is a popular one on the lower end.
 
Something like a MOTU UltraLite-mk3 Hybrid could work. It's $50 more and I can't vouch for MOTU but a lot of guys here use their stuff. It does have more than 4 outputs though.
http://www.sweetwater.com.tore/detail/UltraLite3Hy

I'll vouch for the Motu Ultralite Mk3 Hybrid. It comes with two mic/inst pre's,6 additional line-ins, 8 line-outs, midi in/out, main outs for your monitors, and 8 built-in mixers w/internal effects. Pretty much all you need for real-time tracking. It's small, portable, and will do either Firewire or USB. It can run on Bus power if attached via Firewire - no wallwart needed.
 
 

My vote goes to Focusrite.

Though a bit more than you listed, the Ultralite AVB is exceptionally good at ~$650.

• 4.9ms total round-trip latency at a 64-sample ASIO buffer size 44.1k
• Average noise-floor is ~-112dB
• Extremely flexible routing/monitoring