Rain all the way. I love rainy weather in general, and would even go as far as to say I hate snow. Snowy scenery is beautiful, but otherwise having to stand being surrounded by it for many months is just pure torture for me.
Winter scenery or early autumn/fall scenery (when the leaves change color etc etc.)?
Hmmm...depends on my mood. If there's no hurry and I want a bit of time for myself, then the ferry; if I need to be somewhere quickly, then the tunnel. I'd probably lean in favour of the ferry, though.