I'm wondering which variation of Blackjack gives the house the least edge and obviously, me, a better chance of winning?

Blackjack (6-deck)
Switch Blackjack
Double Exposure
Spanish Blackjack

I'm guessing the cards are shuffled every new hand . If so, can I get some basic strategy on the best game for me to play?

http://wizardofodds.com/

I personally like blackjack switch because as far as im aware its the only game online where I can play 2 hands.

Oh, sorry. To clarify on regular 6-deck Blackjack, I can play up to 3 hands. Switch Blackjack only 2 hands. Double exposure and Spanish only allows 1 hand per play.

Depends on the rules but typically switch has a house edge of something like <.2% if you use perfect switching strategy (counter intuitive switching at times).

typical house edge on 6 deck blackjack is .5% against you.

Continuous shuffle, yes AFAIK.

Online blackjack is -ev all the way it's whatever you find the most fun which you should play.