I use a Wok. Works great for deep-frying and can be used for things like stir frying and does not cost much and uses a little less oil given its shape being wide at the top and narrow at the bottom. You are the temp control, so you have to watch it carefully. You do not want the oil smoking hot, but hot enough to fry. I usually test the temp by flicking a water drop or two off my finger into the oil and see how much it sputters. Then I watch how fast the beer batter browns and adjust heat as necessary. I guess using a thermometer would be better.
I did have a T-Fal deep fryer (I think it was T-fal), the one that has the built-in oil filtration and dumps the oil into a compartment on the bottom, but after not all that much use it just stopped working, (probably something with the electronics) and I then went to the Wok. The Wok has been used for deep and stir-frying for a thousand years.