With my log periodic antenna pointed towards Toronto, I receive the follwing channels consistently or fairly consistently (I'm located in Kitchener):

5 (CBC - Toronto)
6 (Global - Paris)
9 (CTV - Toronto)
11 (CHCH - Hamilton)
13 (CTV - Kitchener)
19 (TVO - Toronto)
25 (CBC French - Toronto)
28 (TVO - Paris)
36 (CTS - Hamilton)
41 (Global - Toronto)

The following channels I receive sporadically:

17 (PBS - Buffalo)
23 (CW - Buffalo)
27 (Global - Peterborough)
31 (CITY - Woodstock)
35 (CTV2 - Hamilton)
40 (OMNI2 - Toronto)
47 (OMNI1 - Toronto)
57 (CITY - Toronto)

When my antenna is pointed towards Buffalo, I can receive pretty well all of the Buffalo stations when conditions are good. Not bad for such a compact antenna!

I feel that any decent UHF/VHF antenna mounted outside at a reasonable height, connected to a preamp and pointed in the right direction will yield good results because we're deaiing with digital signals now, not analog, Signal strength is not the most important factor anymore. Keep in mind that it's the QUALITY of the digital TV signal that matters most.