A hand raised cockatiel is pretty much a perfect easy bird. They are seldom biters and are not very noisy. The males are great whistlers and can learn a few words. Females are quieter, less outgoing and rarely whistle or talk.
I currently have budgies (lots of them) and I adore them, but they're almost never hand raised, so you need to finger tame them yourself. Unless the budgie is less than three or four months old it can take a while for them to calm down and trust you. Budgies are also more nervous and flighty than cockatiels. Males are more vocal than females and can learn to talk. Females are usually less sociable than males.
if you can get a young English Budgie they are much calmer and more docile than regular budgies. They are about 50% larger than regular budgies, with longer fluffier feathers.
Hand raised Green cheek conures are wonderful birds about the size of a cockatiel but with larger, more parrot-like beaks. They can be nippy as they mature.
Other parrot forum members will add their choices.
I hope you find a bird that fits your lifestyle. Good luck.