Actually it depends on your target audience. If your audience is say internet marketers, then Disqus is a good choice as many of them have and use it.
If it's every day people then a facebook one might be the better solution.
Depends on what your audience uses most in their internet travels.
I kind of fought Disqus in the past, but I've come to really like it. About a year ago I was debating on what commenting system is best, I even put together a blog post with some bloggers weighing with their opinions. I ended up using Disqus on everything.
For me, Disqus completely eliminated my spam. And you can even set it to moderate every comment to add more protection. But you can whitelist people you know and trust. So both worlds. Well, other plug-ins offer that. The other thing i like about it is that each comment has social share buttons built in.
One last thing, I recently noticed I am getting a fair amount of traffic from my Disqus profile. And I don't even comment with it that much. So I might do more and see if it translates into money
Only other thing to think about, many bloggers who comment (myself included) do like blogs that use CommentLuv. That extra targeted link is very nice.
No perfect solution.
