Where should I get iPhone 6s? Rogers? Bell? Telus? Apple?

I've been researching their deals online but they are so similar. I'm currently with Rogers and my contract has ended already, so if all deals are similar, I should just stay with Rogers, right?

Another way I'm thinking is buy it in full from Apple then choose a different service. Maybe Wind for its unlimited data?

Please advice.

I've never heard of those companies, Rogers and wind, but let me warn you of unlimited data. It may not be 4g/ 4g lte speeds. You may end up with unlimited 2g or 3g speeds. Sometimes you get unlimited 4g/ 4g lte speeds but end up paying a huge price. Watch out for the term unlimited. That's all. And also, i would buy the phone from your service provider, since 2 year contracts may be cheaper than buying it straight from apple.