Until he wins championship, no for Rams.
1 Vermeil
2. Allen
3. McVay
4. Knox
5. Robinson
Best ever? That's some serious pipe dreams right there.
I second these rankings.
Vermeil not only turned the Rams around, he turned adversity into a Super Bowl championship with Kurt Warner. This was an unimaginable (at the time) and unsurpassable championship run. It will always be the stuff of legends.
Imo Vermeil would have won at least another Super Bowl had certain St. Louis sports writers (who could not accept his success after they had earlier turned against him) not mounted a campaign to kick him into premature retirement. They claimed that the Rams would lose Mike Martz if they didn't promote him to coach. Talk about ass backwards priorities!! Too bad exactly that didn't happen. Unfortunately, Vermeil allowed himself to be talked into quitting.
Not least, Vermeil was and is an extraordinary and gracious human being. Vermeil's loyalty to his players was also legendary. Of course, Vermeil would NEVER have pushed Warner out the door as did Martz.
George Allen was another legendary coach. As George Halas's defensive coach with the Chicago Bears he was responsible for one of the greatest defenses of all time in their 1963 championship year. He then brought his great defensive mind and motivational power to the Rams. A decade of losing seasons they went 49-17-4 under Allen. When the owner fired him virtually the entire team threatened to retire or demand a trade. Allen went on to bring his "the future is now" philosophy of trading future draft picks for capable veterans to the Washington Redskins, taking them to the Super Bowl.
McVay also deserves credit for engineering a massive and immediate turnaround in the Rams' fortunes. He has brought a number of exemplary qualities to the table, including high energy, effective communication and management, great assistant coaches, high precision practices and preparation, a relentless commitment to "win now" reminiscent of George Allen, and of course what appeared in 2017-18 to be an unstoppable offense.
McVay is by any standard an outstanding coach. Imo however the jury is still out on whether his offense as run the last two years will stand the test of time, or whether erosion in talent and familiarity have cut into its effectiveness. If he can duplicate his initial success with Stafford at QB, possibly or presumably with a revamped scheme, he will answer any critics (including me, though I am not really much of a critic and am rooting for his success!!). If so he will also cement his status as one of the greatest Rams' coaches.