For bolt guns, I'm a great fan of Mauser based designs, especially the ones Westley Richards offers.
Lovely wood, steeply angled English style grips, color case hardening, quite a lot of scroll work, but unobtrusive, a fairly long slim barrel, express sights, barrel band sling swivel. The take downs are pretty nice too.
Like this one:
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For Doubles, I like the H&H rifles best, but I do think they look better with either slightly longer than normal barrels, or slightly more slender barrels than you see in the .470+ calibres.
This one for instance, looks a tiny bit 'stubby' to my eyes.
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At a more 'boring and affordable' level, I think Beretta makes a very beautiful shotgun in their 686 and 687 series, especially those with the side plates and the 30" barrels.
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