Kinda depends on a number of factors from how much time you have and how much you're willing to put into them (time, money, learning etc.) to what your wearing habits are and what kinda style your prefer.
I know a lot of the cloth users on here love a prefold or flat including me, but they are a pain with pinning on and learning to fold.
I personally don't like pockets, they don't have enough capacity for me and don't tend to work well in certain positions (like lying down), but they are much more discreet than other types and can be very quick and easy to change, they also take up less space since they use pads rather than a full wrap around nappy.
AIO's seem like a great idea and most "disposable" like but when the waterproof outer fails (and it will, it doesn't last forever) you have to replace the whole thing (expensive).
For me I personally say a fitted style is the best option, it goes on and fits much like a disposable, covers the whole area, including around the sides of the hips, with absorbency (great for side sleepers), is easily boosted with extra pads, can use any plastic pants/wrap you like for waterproofing which means the same nappy can have a plain coloured or printed PP/cover depending on mood and are generally very comfy. Downsides are not so discreet, obvious on a line when drying often a bit more expensive than flats/prefolds/pockets and often made with less than ideal materials (mostly microfibre and fleeces).
In the UK if you want a cheaper option to give cloth a test check out the
Dotty Diaper Co's cloth option, I will tell you they are far from the best (and definitely need a booster or two if you want good capacity), you'll need some plastic pants with them and I can link some good booster pads that work well with them too if you need.
Having warned you they are not the best why would I suggest them?
They are fairly cheap for an adult fitted nappy at £35-£40 depending on size needed have a good fit and are nice and soft, also the fabric they are made from washes easily and dries fast so they are a good starter point for someone looking to try cloth who has no experience, if you decide you like the way cloth feels and you are able to launder them properly we can probably link you to some much better options for longer term use.
If you have the time to put into learning how to fold and pin on a flat nappy and want to try that instead (folding doesn't take long once you are used to it but changing will take longer and require more space to fold the nappy) then both Drylife and Cuddlz in the UK sell Terry flats fairly cheaply but decent quality Terry.