I know this isn't really about brand but I've always liked Leupold. I've owned everything from a Tasco to a Zeiss and I like Leupold. 50 mm is probably the standard these days but I've dropped back to 40 last few years.
“Killing tomorrow’s trophies today.”
On the distance I like to walk to my stands: “The first 100 yards is also the last 100 yards.”