Congratulations.
Depends on your situation.
1)How many people will be in it usually? Just yourself, or a family?
2)What are your main priorities? Safety? Reliability? Style? Features?
For 25k, I recommend that your car have the following features:
1)Vehicle Stability control: This is a MUST in snowy weather. I fishtailed spun out of control in the snow because I didn't have it.
2)Brake assist: Stops the car automatically so that you don't rear end others. Could save you from causing an accident like the one I had just today! And could save you money or even a life.
3)Ipod/mp3/usb connectivity. I don't know how most cars are nowadays, maybe this is standard in most cars.
4)Adaptive cruise control is very nice if you drive a lot on the highways. Just set it on, and all you have to do is worry about steering, no gas or braking required.
There aren't many new luxury cars you could buy under 25k. I would buy a slightly used one (maybe one or two years old). I recommend:
BMW 3 series
Audi A3 or A4
Infiniti G series or Q50
Lexus ES 300
Cadillac CTS or ATS
Buick Verano
Mercedes CLA
Also see
http://www.autobytel.com/top-10-cars/least-expensive-cars/luxury-cars/