I'm partial to the Sightron SIII,I have 5 of the 6-24x50 scopes,and they are a steal for the quality of the product you get. I really like the MOA-2 reticle,it's a great target shooting reticle.But I like hunting with the LRMD reticle,you can see the reticle better in a busy background.
The Viper PST is a good scope,but IMO,the glass isn't as clear as the Sightron. Vortex does offer FFP and SFP reticles and a few other extras that Sightron doesn't,but I will always take better quality lenses over the extras that Vortex offers.
Leupold has good scopes,but they cost about 3x what they are actually worth. I'll take a Sightron SII or SIII or a top end Weaver over a Leupold scope anyday.Leupold lost my business many years ago. Their warranty isn't any better than any of these other brands,they all have lifetime warranties on their products.