It depends on how big your list is for the best players in baseball. If we're talking top 10, no. I'd say he's roughly somewhere in the range of 50th to 75th most valuable player (including pitchers) in the major leagues and that he's more valuable than all of our offensive players except Votto, although you could make an argument for Phillips. Evidence:
Of all outfielders with at least 500 plate appearances last year, he had the
16th highest runs created per 27 outs. As an aside, Drew Stubbs was the worst.
Of all the outfielders with at least 1000 plate appearances over the last 3 years, he is #12 in RC27.
Considering that by my count, there are 90 starting outfielders playing in the major leagues at any given time, that puts him in the 86th offensive percentile, which makes him very good. Conservatively, it makes him just about a top 100 player. But because of his good defense (or perhaps, better stated, the subpar defense of some of many of the guys who hit better than he does), I'd rank him in the top 75 for sure.
Here is the list of the 12 outfielders who have hit better than Choo over the last 3 years (as measured by RC27), followed by the 16 who hit better than him last year. By the way, I agree with the person who said that Swisher was a good comp for the type of contract Choo could have expected if he had hit free agency this offseason. Their RC27 is nearly the same (Swisher a smidge higher) both last year and over the last 3 years. However, Swisher is a couple years older.
Outfielders who have been better offensive players than Choo over last 3 seasons (with at least 1000 total PAs)
Bautista
Braun
Hamilton
Cargo
Holliday
McCutcheon
Stanton, G
Kemp
Willingham
Beltran
Swisher
Outfielders who were better offensive players than Choo last year (with at least 500 PAs)
Trout
McCutcheon
Stanton
Braun
Melky
Hamilton
Fowler
CarGo
D. Murphy
Holliday
Austin Jackson
Cespedes
Willingham
Swisher
Zobrist
Let me put it this way, if Choo isn't "great," then the only "great" non-pitcher on this roster is Joey Votto.