We've all seen how ugly most of Waterloo's student warehouses are but both Waterloo and Kitchener also have some ugly stuff in their cores.
Downtown Kitchener:
This useless, half empty, ugly, out of place plaza has no business in a downtown area but here it is. Thankfully LRT construction will see a station block the parking lots entrances which should render it completely useless and prime for redevelopment.
https://www.google.ca/maps/@43.4488495,-...ulttmHnLgDfz-pQ!2e0!7i13312!8i6656?hl=en
Not sure what the architect was thinking when they built this BMO branch
https://www.google.ca/maps/@43.4498813,-...4bB25_V0lkoU54A!2e0!7i13312!8i6656?hl=en
Believe it or not, this building was worse without the glass when it was originally built as one of two downtown malls to compete with the suburbs. It's now mostly empty with its largest tenant gone leaving the slowly dwindling local daily newspaper staff, a Goodlife, a for profit college, <5 foodcourt stalls, and ~5 other crappy mall shops and a crumbling parking garage.
https://www.google.ca/maps/@43.4491508,-...uvMpHtyiY1wFWiA!2e0!7i13312!8i6656?hl=en
https://www.google.ca/maps/@43.4503171,-...O34cqdJ9hszlW-A!2e0!7i13312!8i6656?hl=en
https://www.google.ca/maps/@43.4496704,-...kagdnzT6u54hF8g!2e0!7i13312!8i6656?hl=en
https://www.google.ca/maps/@43.4485583,-...Aa7FjClslyZ6WfA!2e0!7i13312!8i6656?hl=en
Not one redeemable angle.
Even more annoying is the fact that it replaced our old city hall just to have the city pay back the proceeds of the land in leasing the adjacent tower. Thankfully they saved the clocktower and pediment. The tower is ok but one wall is completely blank. With a pretty dismal occupancy rate and a growing local economy coupled with an LRT stop out front we might see it redeveloped since the owners have deep pockets.

jameshowe.ca
https://www.google.ca/maps/@43.4501697,-...3.78204%26pitch%3D0!7i13312!8i6656?hl=en
http://2.bp.blogspot.com
A true slice of Bavaria right in the core... Nothing says German heritage quite like a stucco castle with no windows
https://www.google.ca/maps/@43.4484691,-...3DvzOGWiGdzc0og!2e0!7i13312!8i6656?hl=en
The now empty former provincial courthouse is one of one a few local brutalist pieces but you can judge for yourself if you think it's worth saving
https://www.google.ca/maps/@43.4533864,-...QSzTK5-C520fYdw!2e0!7i13312!8i6656?hl=en
Uptown Waterloo:
While not particularly ugly on their own the monotony of these towers and the suburban-like layout in an urban core make them bad (more towers still to be built):
https://www.google.ca/maps/@43.4652049,-...YDt5zJnjz43TUhg!2e0!7i13312!8i6656?hl=en
Marsland Place has been basically the ONLY highrise inside of Uptown since it was built. Just look at those soaring large windows, beautiful exterior, colour, and of course excellent street interaction:
https://www.google.ca/maps/@43.4648475,-...CbaMZEUDSMi502A!2e0!7i13312!8i6656?hl=en
Allen Square is a bit of a bunker as well:
https://www.google.ca/maps/@43.4602777,-...7.34879%26pitch%3D0!7i13312!8i6656?hl=en
Suburban Tim Hortons right on the edge of the core? Check.
https://www.google.ca/maps/@43.4691577,-...9.54572%26pitch%3D0!7i13312!8i6656?hl=en
And finally, someone decided to butcher this building at some point in its life.