Manual frother (Pannarello)
You hold the jug under the wand and froth yourself. Affordable, easy to clean, takes a little practice. For example the De'Longhi Magnifica S, Philips 2200 and Gaggia Anima.
Milk carafe (e.g. LatteCrema)
Attach the carafe and the machine froths and dispenses milk and coffee automatically. The carafe then goes back into the fridge with the remaining milk. For example De'Longhi LatteCrema and the carafes from Saeco and Gaggia.
LatteGo
Philips' two-part system with no tubes: pour in milk, press the button, then rinse under the tap. Exceptionally easy to keep clean.
One-touch with milk tube
A tube draws milk from the carton or a container, and the drink is made at one touch. Convenient, but the system should be rinsed after every use. For example on JURA, Siemens and Melitta machines.