I started with a Weber Smokey Mountain. Charcoal smoker, very simple, requires some attention as you may need to adjust air inlets, add fuel or add smoke wood. Turned out some great food on this little smoker.
Moved on to a Traeger, Lil Tex Elite pellet smoker. Super easy as
@obullfish said. You can also use it like a regular grill, you can bake on it, you can make pizza on it. Their customer support is top notch - best I’ve ever experienced from any company.
My last purchase was a Stumps Baby gravity feed smoker. It’s a charcoal smoker and you add smoke wood to the ash pan. I wish I had the time to use this smoker more often. It is dirt simple, holds temperature like nothing I’ve ever seen, extremely well insulated, can hold temps from 225F all the way up to 450F for hours and hours. Get a monitoring system like the ThermoWorks Smoke and it’s essentially set it and forget it. Only downside is the price, but you do get what you pay for.
I feel all 3 have their place. The Traeger has handled the bulk of my cooking duties just based on its versatility. However, when I have a long weekend and plan a smoke, I’m going with my Stumps. Over the July 4’th weekend I smoked 4, 9 lb pork butts and 2, 11 - 12 lb briskets that turned out awesome!
There are many out there. I’ve heard good things about Big Green Egg and Camp Chef, but I personally have not used them and cannot offer an opinion based on personal experience.