The Cauldron is great, because it give a 2.25% to everything, plus the Witch Marge costume offers increased payouts for all tasks, PLUS you can crank out some serious daily cash by planting 4 hour Silvertongue all the live long day! This one is a no-brainer.
I'm loving Boobarella, but there are cheaper standalone characters that payout the same. The Ghost Zapper looks like a ripoff. The Freakmobile is extremely cool, but at 35 donuts for a .75% bonus, it doesn't match the beauty of the other vehicles for 40/2%.
The only premium item I'd recommend that doesn't offer any bonus would be Barney and the Bowlarama. It's expensive, but it's Barney. You've probably seen his tasks in other towns, so you know what you're in for.
Duffman rocks. Probably my favorite.
And Otto and Mel also have Premium-earning tasks in Krustyland.
