The answer is ...................... well, a lot depends on what the meaning of the word "best" is to folks that enjoy photography as versus those that make a living out of it as versus those that obsess over it.
For me, the 70-200 f/4 L IS wins best of show for balls-to-the-wall performance; unfortunately it's the least used lens in my bag. The lens is nice and light which makes it easy to keep on your lap while driving around between landscapes Point-A and Point-B and looking for wildlife opportunities in between. Nothing special here, just a drive-by shooting at Canyonlands NP that could have been taken with almost any camera/lens combination you can think of.
The 100-400, although not the greatest from the standpoint of optical performance is used more than any other lens I own (small length at minimum pull makes it easy to store/carry, very small MFD makes for great "keep your distance" close-ups, and a nice 4:1 zoom range). Here is are two examples of the small value of MFD coming to my rescue.
From one extreme to the other: 70-200mm f/2.8L IS Mark II at around $2.4K for its prime-like optical performance and superb IS and/or EF-S 17-55mm IS (with plastic mount ) at around $90.00 for the best bang for your buck. The performance of the cheapo lens is no slouch either. Well, it is actually very good regardless of the price.
Oops, a typo up there - I meant the cheapo EF-S 18-55mm f/3.5-5.6 and not the 17-55mm f/2.8 IS.
I only own two and don't use them much since i upgraded to full frame.. 18-55... and the other remarkable 55-250..
Actually the 55-250 is pretty darn nice I guess that gets my vote?
If i could vote for my zeiss 35-70 I would.
I don't have anything fast past 85 1.8 and have a Tokina 11-16 2.8 so fellow canon zoomers where do i start?
I've been searching out an 80-200 2.8. I don't want anything that's super heavy hence why i carry around primes often.
I am sure 70-200mm F2.8L IS mk II will beat any including Pipe Other than this two #1 and #2 I would say F4 IS is next (#3), I like mine 16-35L mk II since very sharp copy and great colors/contrast.
Well, I sold my two favorite zooms, a great copy of the 'pipe' and my 70-200 f/4L IS to buy a 70-200 f/2.8L IS II. Jury's still out on that one, but I like is so far.
My 24-105 gets the most use however, but I didn't have the love for my 100-400.
