My main league is a 12 team NL-only auction league. Roto 4x4 with 25 man rosters.
After the draft, hitting is hard to come by. Pitchers can usually be found.
I really like the deep league, but finding that 5th OF or 2nd C is difficult.
that is exactly like my AL league, except by going 12 teams deep in the AL, you have to scramble even harder. I've heard of 13 team NL leagues.
We also throw in a 2 round farm draft. You are allowed to keep 3 farm boys up until they lose rookies eligibility. Last year, my "farm" was Andrus, G Beckham, and Reimold, and the year before I had Ellsbury at the start of the year. Farm boys get assigned $10 when activated. I would love to this in an NL league because the NL has had so many of the best prospects in recent years.