Unfortunatelly, I can’t help you much with third party options, except for Zeiss, which is manual focus only (for Nikon) and even more expensive than native lenses.
Main problem which I historically had with Sigma, Tamron, Tokina was quality control and auto focus compatibility issues.
I am even not following much their recent offer, but I would suggest you to look for the reviews on photozone.de, because Klaus is making good quality tests and his findings are usually in line with my experience.
I like Samyang lenses for their optical qualities – 14/2.8 (not for architecture, but great UWA for landscape), 24 and 35/1.4, both are great astro-photography lenses because of superbly corrected coma, 135/2 is amazing short tele and even 85/1.4 is interesting, because of very smooth bokeh.
I tried few Sigma lenses, 85/1.4, 35/1.4 art, 50/1.4 art and new 150-600 Sport e.g. They were all nice lenses optically.
I had before Tamron 70-300 VS USD and it was nice budget lens too, better than its Canon counterpart.
Tokina had great 11-16/2.8. With all those however, it was problem to pick the piece that wasn’t de-centered and that will focus accuratly. Not that I spent too much time looking for good samples…