Reicast
Reicast is a Dreamcast emulator developed in part by some of the developers of NullDC. The idea behind the project is to make a Dreamcast emulator that is both highly portable while also being fast and retain a great compatibility rate.
While being extremely tough goals to actually meet, the team is knowledgeable enough to be able to pull it off. Reicast is one of the few remaining Dreamcast emulators that are still continually being developed.
Reicast is capable of rendering Dreamcast games at a higher internal resolution, allowing them to look much nicer on a HD screen then just stretching the original image will.
However Reicast, much like the emulator it is based off NullDC requires the Dreamcast BIOS to be able to run, while we cannot provide BIOS files here due to there copyright nature there not the hardest things to come by.
The Windows builds of Reicast have not really been tested, we instead recommend those who are running on a Windows PC to check out NullDC or DEmul.