Any good Bistros in Toronto-Don Valley
Gotcha -- I'm guessing you are staying on or near Don Mills. Yonge is about a 5 - 10 minute drive along Eglinton. Lots of great options near Yonge and Eglinton. Tabule is a fantastic Middle Eastern place, but it may not be open when you arrive, as they are expanding into the space next door. Give them a call. You can find them at http://www.tabule.ca
Just up the street from Tabule is Coquine, a great French bistro. Mirabelle is a cute little wine bar. Zucca is excellent, casual Italian.
On Mt. Pleasant (the main street just East of Yonge) is Zee Grill for fantastic fresh fish and seafood. Lai Toh Heen is quite upscale Chinese and the sister restaurant to Lai Wah Heen, which is downtown and has phenomenal dim sum.
Have a great trip!
Depending on where you're staying and how you're getting around, there are a couple of neighbourhood spots on Laird, just south of Eglinton, definitely unpretentious and local faves. If you're closer to Yonge than Don Mills, it may not be worth your while but if you're in the area:
Marvellous Edibles - bistro-ish (also serves breakfast) --
Old Yorke seafood/fish&chips
120 Laird Dr, Toronto, ON M4G3V3, CA
96 Laird Dr, Toronto, ON M4G3V3, CA