The best streaming devices are going to be either the Roku box or Amazon Fire TV box. If you already have an Amazon Prime account I would recommend the Fire TV over the Roku but I have had both and you can't go wrong with either. The reason I specified the box is that you are going to get more a consistent streaming quality from the boxes as opposed to the sticks.
As for the services, the big 3 for live streaming would be Sling TV, PS Vue, and DirectTV Now. I've used all 3 and while I currently have DirectTV Now, but that is mostly because I got in on the ground floor and have an incredibly hard to beat deal. I would recommend looking at the available packages for Sling and PS Vue and seeing which ones have the channels you need. Also, keep in mind what features you may need, such as the ability to stream on multiple screens at once, Cloud DVR, and the addition of premium channels.
Hulu Live TV looks very promising but I don't have any personal experience with the service and the Live portion is still fairly new. I will say, the Hulu streaming service has been good however the layout isn't the most user friendly at times.