• The newer set of Ziplines in Whistler are "Superfly Ziplines". The winter tour includes a snowcat ride up Rainbow mountain, and then you zip four lines to the base. The first two lines are the longest lines in Canada, 1.2 and 1.3km long.
Superfly Ziplines
• Snowshoeing is offered right on Whistler Mountain with The Adventure Group. You can add the Peak-2-Peak pass to your snowshoe tour (for a way discounted rate). Good couples activity, and then you can head up and do the Peak-2-Peak gondola.
Welcome to TAG ? Your Guide to Whistler Activities | The Adventure Group
• The dinner tours by Whistler Tasting Tours are incredible. You choose one of two options, each including four stops in Whistler. You essentially do one course of a meal at each stop. Add the wine tasting, and if you know nothing about wine be sure to ask questions about the wine and why they've paired it with what you're eating.
Whistler Tasting Tours - Explore Best Restaurants in Whistler BC
• The Adventure Group also offers Snowmobile Tours, and for couples I would recommend the new dinner tour this year. You'll head out for a snowmobile adventure, and stop at the Mountain-top Yurt. There you'll be served a three course dinner by Bearfoot Bistro, one of the top restaurants in Whistler. Following dinner you snowmobile back to the base.
Welcome to TAG ? Your Guide to Whistler Activities | The Adventure Group
• The most unique spa in Whistler is by far the Scandinave Spa. Couples massage, or just simply enjoy the baths for a relatively inexpensive price.
Scandinave Spa Whistler. Your Day & Resort Spa
• "Tandem Sled downhill" was a company called Snow Limo. They're not currently operating on Whistler Mountain, but they can be found at Grouse, Big White and Sun Peaks.
Snow Limo Tours Ltd | Whistler, Big White, Grouse Mountain
Full Disclosure: I am the Group Sales and Special Events Manager for TAG Whistler. Doesn't really effect anyone here, unless you're a group over 12 guests or looking to propose to your significant other. In that case, PM me! Ha.
-Dave
EDIT: The above post was written while I was working for TAG. As of Jan 2014 I am now Owner/Director of Classic Car Adventures. Please do not PM or email me looking for deals in Whistler, as I am no longer able to hook you up for reduced activity pricing.