Best projector? I'm not sure if that is the question/comparison to ask, one could spend $100,000+ on a projector.
If you limit your options to 1080p projectors, mid grade (say 2.5k-5k) they can easily keep up resolution and clarity wise. But this is really apples to oranges, and unless you're limiting yourself to 90" due to space constraints it doesn't make sense to compare like this IMO. I'd be asking myself (and did) if I could integrate a projector into the space with the inherent drawbacks of a projector (none of which are video quality related with a decent projector).
I think many people that have projectors, myself included, would rather have a panel... IF it could be the same size and same cost as projector offerings. Many with projectors run 120"+ screens, there is no available TV in this size, and if there were if would require a strong second mortgage. Right now the size/cost equation isn't even close, or even possible due to panel size limitations. For a lot of people with dedicated rooms however a projector makes the most sense, since light is easier to control, and it's the only way to get a suitably sized picture.
My screen is approaching 2x the size of a 90" panel, with good 1080p content it looks amazing, and the lens on my HW50 is known to not be the sharpest. The detail it brings out rivals some of the best out there, however a larger picture also brings out source flaws much more as well. No doubt 4k would be a game changer on picture sizes this big, but the cost is still fairly high and the technology is obviously it it's infancy with little to no content available.
What are you looking to accomplish?
Home Theater Build in Progress (Contemporary living room, Klipsch RF-7 II 5.2 audio, Sony VPL-HW50ES Projector, Da-Lite 16:9 159" HP, recessed Mid Atlantic rack, etc)