The original question of this thread was "Does He Love Her?" not "Do They Love Each Other?" or "Who Loved Who The Most?" or any of a dozen other variations. Does Spike love Buffy? Absolutely. He proved it over and over, enduring torture, protecting her and her family from her enemies, regaining his soul, and simply being there for her when no one else was. None of Buffy's other lovers endured so much and received so little in return as Spike did. SPIKE LOVES BUFFY. Period. I don't see how anyone could doubt that, considering what he went through to prove it.
The companion question is, "Does She Love Him?" This is where the Spuffies, Bangles, the Fuffies, the Billows, and all of the other shippers tend to drift apart. Some will say that Buffy could never love someone who tried to rape her (of course, I might point out that those same people have no problem with her loving a vampire who tried to kill her AND destroy the world). The truth is, as much as I believe that she does, as much as I WANT her to, neither I nor any of the other fans can say for sure, because of the evilness of he who created the Buffyverse, the Almighty Joss has always been so ambiguous in the matter.
I will say this, and I will continue to say it, and believe it: If there is anyone in the Buffyverse who has earned Buffy's love, it is Spike. If she's too shallow to see what he's offering her, she doesn't deserve him. He should start stalking Faith.