I live in LA but grew up in Toronto and my parents have a cottage on Niagara on the Lake so I visit when I can. The Niagara region is under-rated. There are some great wines there. White wines and the ice wines are generally better than the reds (as many feel young) but I was surprised by some great finds:
Stratus is one top of my list. Southbook is up there too.
I'd also suggest: Frogs Pond, Coyote's Run, Jackson Triggs, ...there's an area called the Bench...Jordan area, it's close - some good ones too. 30 Bench; Daniel Lenko (by appointment - awesome chardonnay); Malivoire (sp?);
The Riverbend hotel has a great restaurant with wineries from all over..their main one is Reif but they have others...