I want to make a dinner table with crossed table legs made of tree branches with the bark still on (raw, no stain/finish/veneer). What type of tree would be best to use to make it stable and won't have the bark come of?
Well, if you want the bark to stay on, (at least best chance) When is more important than What. Wood cut in late fall or winter, after the tree goes dormant and before the sap starts flowing again in the spring.
The tree 'dries' itself out and the bark stays attached to the wood much better. In the spring just when the sap is starting to run is the worst time to try and keep the bark on and the best time to cut wood that you want to peel the bark off.
Oak and Hickory (shag bark) cut in winter will keep it's bark for a long time.