My favorite red dot sight - Holosun HE507C-GR-V2 Green Dot Sight

First the bad. . . It's a little heavier than many others in this price range (for example, the Vortex Venom and the Burris FastFire 3) and its included Picatinny mount could have a somewhat lower profile. That aside, everything else about this sight is fantastic. It looks great, it's built like a tank, the 3-reticle design is incredible, and the green dot is easier to see. With the dot-in-the-circle as your chosen reticle, acquiring the dot is painless and is impossible to miss. The up/down buttons are large, and so having a slightly heavier sight to accommodate these buttons is worth it. Easy battery exchange. Beautifully built and beautifully packaged.