Which Canadian province is most socially conservative?

[DC Al Fine]

If you look at the Political Compass' data on abortion, gay marriage, and euthanasia, Saskatchewan is the most conservative, although Alberta is in 2nd place. The most socially conservative riding is far and away Provencher (Vic Toews' old riding).

[DC Al Fine]

Evangelical population by province, 2011 NHS:

Newfoundland and Labrador  81,315  16%
Prince Edward Island  19,590  14.3%
Nova Scotia  140,585  15.5%
New Brunswick  131,655  17.9%
Quebec  294,090  3.8%
Ontario  1,605,965  12.7%
Manitoba  225,735  19.2%
Saskatchewan  147,840  14.7%
Alberta  596,020  16.7%
British Columbia  641,005  14.8%

(I followed the definition here: http://files.efc-canada.net/min/rc/cft/V01I02/Evangelicals_Canadian_Census.pdf)

In Newfoundland, it's dominated by Salvation Army and Pentecostals, Baptists dominate the Maritimes evangelical population, Ontario is pretty mixed and includes a lot of Black churches, Manitoba gets a boost from the Mennonites, the rest of the West is very mixed. 

Comparing the 3 Prairie provinces:

Manitoba is 19% evangelical, 21% mainline Protestant, 26% Catholic, and 26% no religion.

Saskatchewan is 15% evangelical, 26% mainline, 30% Catholic and 24% no religion.

Alberta is 17% evangelical, 16% mainline, 24% Catholic, and 30% no religion.

Why are Baptists considered Evangelical and non mainline?

There's no Canadian equivalent to the mainline American Baptist Churches USA. Every major Baptist denomination is a member of the EFC, and the remainder are mostly either Reformed Baptist or Independent Fundamental Baptists which are even more conservative.