I really like the MILLET model SP1.
Have had one on my Ruger Mark II for years now, and that set up sure is a deadly small game getter!
The Ultra Dot is also a good one, a friend of mine has had one on his Freedom Arms .454 for years. He shoots it A LOT w/full power loads and that red dot is still doing great!
Hope this helps, good luck w/ your decision
Del