Marlin. Over the years Marlin quality has been consistently very good. Recent new guns since being sold to Remington may be suspect. Winchester quality on the other hand has been all over the place. Many of the 94's have been pure junk, others every bit as good as the Marlin. You never know until you buy it and start shooting. Unless you are buying from someone where you know the guns history a Winchester is a bigger gamble than I'd recommend.
Marlins will be a bit heavier, but are almost always more accurate. Reliabity is about a toss up.