Low sec hacking was netting me maybe 20M a site on average. Not bad for a few minute's work, but the big money's still in plexes.
There's a Guristas 6/10 that pops up fairly frequently in Caldari low sec, it's easy solo in a Tengu, Ishtar or Drake, but I'm sure we could work something out for groups of newer players. The drops are random, so there's always a chance of poor loot, but there's a decent chance of coming out with hundreds of millions worth.
I haven't done much w-space exploration, but me and a friend were blitzing through c3 and c4 sites with 3 battleships. Prices have probably changed since then, but we were making maybe 100m an hour each.
EVE Online: Letava
Formerly known as White Thrall