You don't look old enough to know what a croquette is. Back when I was your age, any cook book worth its salt had recipes for salmon and turkey croquettes. But now those recipes hard to come by, probably because of our national fear of deep frying. (Alton Brown has a recipe for tuna croquettes that's actually a sauteed patty. Paula Deen's salmon croquettes? Same thing. . .a patty.)

These two recipes come the closest to duplicating good old-fashioned 1950s croquettes. Both recipes have plenty of wiggle room to safely fool around with different meats, cheeses, peppers and other vegetables.

http://www.spain-recipes.com/croquetas-jamon.html

http://dinersjournal.blogs.nytimes.com/2008/10/07/making-spanish-croquettes/

And for dessert, A&M have a recipe for Rice Croquettes in the dessert chapter of "The Essential NY Times Cook Book."

First let me second (whose on third?) innoabrd's suggestion of stuffed olives; these are traditional to the Marche region of Italy, specifically Ascoli Piena. Ground meat would be the typical filling.
But if I had a new fryolator I would be cooking arancini like crazy. These rice "croquettes" are made with short grain (arborio or the like) rice with a cheese and savory filling. The name comes from the Italian word for oranges. Because that's how they are shaped. Although they sometimes take different forms depending on the contents.

I too envy you the fryer but can't justify it. It would have come in handy last weekend when I made coconut shrimp for a party. Good luck with your hunt.

I tested these awhile back and they are amazing and I am, in fact, planning to make them again this weekend!

http://www.food52.com/recipes/4406_artichoke_fritters

Not a croquette, strictly speaking, but deep-fried olives!
Don't remember where I got the recipe, but basically I did the basic egg and crumb thing, but stuffed them with a variety of things: cheese, roast peppers, anchovies, etc. Anything you can stuff in there...

I do so want a fryer, but not sure that I'd be able to stop...

Judith Jones had a recent book that was part biography and part cookbook where she gives a great croquette recipe. Basically you make a thick bechamel, then fold in some kind of chopped meat (chicken, ham, beef, fish or whatever). You let this mixture cool and then form the croquettes, which you then dip in floor, egg and bread crumb. Then deep fry them until golden. Oh, you can put some cheese in the middle -- we've done cheddar with Ham croquettes. They're excellent.