Crisco may be odorless but it's also loaded with trans fats, which are major causes of atherosclerosis and other forms of coronary disease. So I'd avoid Crisco like the plague.
Also I would avoid soybean oil. It can have a very strong, unpleasant odor.
The best oil for deep frying is peanut oil. It is full of good fatty acids, and doesn't go rancid nearly as quickly as other oils like safflower or canola (which by virtue of their polyunsaturates will oxidize quickly).
Frying oil can be re-used several times. It will stay fresher longer if you don't let any salt or acid get into it. That means, add the seasoning to the fried items after they have finished frying and are out of the fryer.
You can tell when a frying oil is going bad. It will thicken, darken, develop a rancid flavor, and get sticky. At that point, throw it out (or recycle into your diesel).
I have an Oster fryer I picked up a couple of years ago at Costco. Cost about $35. It works great; has the immersion heater, a good thermostat, and a reasonable capacity. The pan is removable, stainless, and can be washed in the dishwasher, but I find it's easy enough to wash by hand. It doesn't emit any spatter when frying with the lid down. I usually set it up on top of a cold range under a running hood to keep any cooking/frying odors out of the home. Mostly I make french fries with it.
