I like them all really! Individual pieces might be difficult, but that’s part of the fun. One of my all time favourites is walnut because it looks fantastic IMO and turns like butter even when dry. Apple also looks fantastic and is easy to turn, but difficult to find much of a good size. Beech is also nice for bowls, but a little bland to look at. I’m still working through a 4 inch thick plank I bought cheap at auction, it had some rot at one end and so nobody else wanted it. I cut the rot off and the majority is sound with large spalted, chocolate coloured area running through it. I’ve made some very nice rice bowls with that. One of my best ever auction bargains was a load of really long 4 inch square posts. They looked a bit ropey, but were correctly described as sycamore and nobody else was interested. Absolutely beautiful, bone dry and spalted. They turn absolutely beautifully and I’ve made everything from lamps to pepper grinders from them!