I've had my nails done at more than 10 places in downtown toronto, north york and GTA, and carnation nails is hands down THE BEST nail place for gel nails, with the friendliest staff.
I have gotten my nails done twice with them and will be back soon for my third set. They can basically customize anything for you, pattern, shape, and even the thickness of your gel. Their almond and rectangle shapes are to die for.
The guy here also gives awesome recommendations if you are indecisive like me.
Make sure to call advance, this place is usually packed!