How many NHL teams havent been to the playoffs?

That has occurred 135 times since the 1926-27 season (when the NHL took sole proprietorship of the Stanley Cup) up through the 2009-10 season.

35 x Toronto Maple Leafs

26 x Montreal Canadiens

17 x Calgary Flames

15 x Vancouver Canucks

12 x Edmonton Oilers

10 x Winnipeg Jets (1)

7 x Ottawa Senators (2)

6 x Quebec Nordiques

6 x Montreal Maroons

1 x Ottawa Senators (1)