Only real standout marker for me in terms of classic design is the Automag.
Cockers deserve some respect for being the most evolved design of all time - but they're not exactly an elegant bit of design are they?
There was an interesting post on Automags.org, where Tom Kaye was asked which marker he'd use other than an AGD product.
If I wasn't in the industry but know what I know now.....
I would shoot one of the earlier Angels. I know John Rice and I respect him as an engineer. They made the parts themselves and most were hand fit together ( the breaches were numbered). When your hand fitting parts someone is testing it to make sure it is right. The early cut and carved were great looking guns and the overall design was more elegant than the typical stacked tube. There was a shoot down problem but I could have fixed that.
For a mech I would want a gun I never had to mess with and didn't have to think about, so I would just shoot a Tippy with everyone else.
No other guns impress me at the gut level. The DM's came from the only gun design to be sold three times because of issues. Bob Long called me when he had gun problems. SP never designed anything and the Cockers were for tinkerers.
Things like Egos, Timmies, modern Shockers etc are all just rehashes of someone else's ideas.