Dimpflmeier's is the best German bakery in the GTA. It's likely the only one. You've probably seen their rye breads around town. Much more can be found at their main bakery in Etobicoke.
It is a large bakery or a small plant, but they don't lose out on quality. I really like their Kimmelweck buns--buns with salt and caraway on top. They need to be eaten the day they're made or the salt drys out the roll. Dimpf's pretzels, danishes and stollen is pretty good too. Go during the week if possible. It can get really busy with Mitteleuropeans on the weekends.