this poll question is ridiculously vague...
"which CPU manufacturer is the best?"... the best what?
if you were to ask who makes the best processor, I would say Intel, but that doesn't make them "the best manufacturer".
<begin_rant>
the fact is that up until the C2D's were released, Intel had been producing underperforming (pentium4) processors for years and at the same time convincing the [un-computer savvy] general public that it was the best, most advanced processor money could buy. and sadly, most people believed it. now with the C2D's, things have changed, now they are actually telling the truth when they say they have the best
now AMD is no angel either, they are no mom & pop store, they are a big corporation too, and if they were as big as Intel, then they would probably be no different from Intel... but the truth is they simply don't [and never did] have the marketing/mass-deception power that Intel had. with that being said;if I was forced to choose between Intel or AMD, I would support AMD for the sole reason that they are the underdog when comparing the two giants.
however, given other current choices I would choose VIA, for one reason because they are even smaller
but that's not the only reason; they actually make great processors that consume very little power, and run so cool that they don't even require a fan. they are also are leading the way for sff/embedded CPU/systems; for example, the new pico-ITX form factor is so small that you could theoretically have a fully functional computer that is the size of a clock radio. with advances like this, the giant ATX systems that we know and love will be a thing of the past alot sooner than you think
</end_rant>
so who is the best? well, in the form it was asked that's a question that will be perceived differently by each person who reads it, therefore resulting in an infinitely inaccurate answer. with that being said, I proudly voted for "other"