Well I agree with this except the Cordelia that cared about anyone else but Angel disappeared in Season 3 didn't she? The prime example of this to me is her utter abandonment of Wesley in Season 3. Wesley, who I always thought was a much closer friend to her than Angel, given that as you say they had a potential romance in BTVS s3, they grew to be friends/co-workers in s1 and were always together when Angel was away doing his solo missions, and then in S2 when Angel alienated her, fired her and distanced himself from her in Season 2. But instead she forgives Angel at the drop of a hat and after that it seems to be all she cares about. She really can't be bothered with Gunn either but I guess he is off dealing with his own drama. So unfortunately, by the time we reach YW, I'm not all that surprised that all she does is services Angel's needs. Cordelia deserved her own story, her own interesting and compelling love interest, her own personal demons, her own growth (like we saw with Wesley).
I will say that I'm not surprised by the number of people who voted Cordelia v. Buffy, but I do find it interesting that the majority of opinions are that "Cordelia deserved a proper send off." Putting aside the question of Cordelia's proper send off (lets say for a second she gets her send off as well in another episode) - do you all still think she was the best person to set Angel back on his path?
I realized I never answered this question completely. I do believe that Buffy would have been the best choice to set Angel back on his path. Buffy was the person who inspired Angel to find his path and mission to begin with. She first inspired him to get out of the gutters and make something of himself and then after he came back from hell she again instilled in him the idea that despite how hard life gets, that you have to keep fighting, even if fighting is all that you do. Those are lessons he carried with him throughout his time in LA, to be reminded of those things again would have been a great way to remind Angel of where he came from.
Also, Buffy is the only other person out there who knows the enormous responsibility that it means to a warrior for the powers, and she is the only other person who understands what it means to lead an army into battle the way that Angel is about to do. She just had her battle, she could impart her lessons, her ideas regarding strategy and provide support and motivation for him. Angel respects Buffy, they worked along side each other for years so I know he would welcome her input.
Finally, the show started with the story about how Angel had to leave Buffy but showed how much he still loved her. In EoD/Chosen & Season 5, Angel's feelings for Buffy are highlighted and it is evident he still loves her. It would have been nice for the male lead to have a moment on his own show with the love of his long life. The same as Buffy had with him on her show.