I like looking at lists of accomplishments in these types of discussions - and so I went to the simplest set of lists I could find. But first, I want to stipulate that I believe the SEC was the strongest conference this year, as the Big South was last year 
- Congrats to Florida and to LSU. I have met Coach Maneiri (had dinner with him actually) and liked him a lot. Both he and Coach O'Sullivan clearly know what they're doing.
Onto the lists:
What I see in these lists, spanning all of CWS history is the following.
- The Pac12 has the most championships, 17. Next is the SEC at 11. LSU is tied for the 2nd most titles (6). USC is first with twice as many - 12. If you group all of the current Pac12 schools into the equation even if they weren't in the Pac12 when they won some of their titles (e.g. ASU, Arizona), then the Pac12 number is 28!!
- The SEC puts more teams into the CWS at one time more often than any other conference - but a relatively recent phenomena - Pac12ers would say some of that may be due to SE bias in the selection - more teams, more chances for appearance in the finals
- Historically, the SEC only has the 7th best team (tie) in CWS appearances (LSU)
- SEC only has the 8th best team in CWS wins (LSU again) - the Pac12 has 4 of the top 7 teams in that category - if you wanna talk about historical depth
- SEC only the 5th best team (LSU) in CWS finals appearances - the Pac12 has 3 of the top 4 - there's that depth thing again
I dunno - I would agree the SEC was the best conference this year. And I would agree if someone wants to say that LSU is one of the best 7 or 8 programs ever, maybe one of the best 3 or 4 if you count titles (tied for 2nd with 6). But I'm not sure that I buy that its the best college baseball conference in totality. But I could buy that the Pac12 is the best baseball conference...ever. 