For intelligent life, there are several things that would probably be true
If they're varniverous/omniverous, they'd probably evolve similarily to us. Depending on the other creatures in their environment, they'll have similar style of teeth, and front faced eyes. If they're herbivores, then they may have side facing eyes and grinding teeth. They'll probably also have opposable thumbs, as those were huge advances in evolution that would probably show up elsewhere, as the creme de la creme of creature's evolution wants to grasp something. If they're large like us, they would probably need to respire oxygen, as oxygen is a huge contributor to our ability to be active, intelligent creatures. They'll probably have at least somewhat similar lungs to ours, as they're a simple way for oxygen to be utilized. They would also probably have a relatively large head, similar to ours, in order to accommodate a large brain.
They'll probably have a similar body structure to ours (in that they'll have a head, appendages, and a definite front and back side) because that is sort of the basic structure of higher life forms.
Apart from that, there would be an unlimited amount of variation depending on the environment of the planet they evolved on.
Then again, this could all be bunk and an intelligent alien could just be a sapient puddle of slime.