A good mid-priced porro-prism binocular such as the Orion Vista will be good enough for most people. If you want the best, look into the Nikon Prostar or Fujinon Polaris binoculars. The Canon image-stabilized 15x50 is another good, premium astro binocular.
Many of the lower-priced models from Orion, Celestron, and others will do fine. You'll get a little more distortion towards the edges of the field, and maybe a little less light throughput in the cheaper bins. For astronomy, you can dispense with extras such as rubber armor, weatherproofing, online drugs and center focus. Porro-prisms are better for astronomy than roof prisms, because the roofs can show a bit of a spike on bright stars. Avoid models with polarizing or anti-haze filters or coating - fine for daytime use, but their light throughput is considerably reduced.

 

Zhumell 20x80mm SuperGiant Astronomical Binoculars
Zhumell 20x80mm SuperGiant Astronomical Binoculars
Paypal   US $55.00
Super Astronomical Zoom Binocular Telescope 15 180X100
Super Astronomical Zoom Binocular Telescope 15 180X100
Paypal   US $72.39
Barska Giant Astronomical Binoculars 25x100 and 40x100 w Tripod Hard Case
Barska Giant Astronomical Binoculars 25x100 and 40x100 w Tripod Hard Case
Paypal   US $999.00
Celestron SkyMaster 25x100 Astronomical Porro Prism Binoculars 71017
Celestron SkyMaster 25x100 Astronomical Porro Prism Binoculars 71017
Paypal   US $259.00
Celestron SkyMaster 20x80 Astronomical Porro Prism Binoculars 71018
Celestron SkyMaster 20x80 Astronomical Porro Prism Binoculars 71018
Paypal   US $114.45
30x60 Binocular Astronomical Monocular Telescope for Outdoor Activities
30x60 Binocular Astronomical Monocular Telescope for Outdoor Activities
Paypal   US $23.80