I still feel that readers qualify as "marked" - they're just an easier form of marked deck to use.
My personal favorites are still the Ultimate Marked Deck, the GT Speedreader Deck and the Gambler's Deck, though I'd prefer a Gambler's Deck that was just a little more subtly marked. The new Gambler's are available in Maiden Backs, which is nice, while the Speedreaders are in Mandolin Backs and the UMDs (if you can find them!) are Rider Backs. Older Gambler's Decks were made in a generic back and in the Rider Back.
I'm actually going to be working very soon on a special home-brew project for a real "secret weapon" kind of deck akin to the Gambler's. More info on that project as it becomes available...