I’m partial to Ayas, where I spent a good deal of time including working on trail maintenance. A village like Champoluc has a bus link to Verres, from where you can catch the train to Turin/Aosta, and there are cable cars from the village to higher up. There’s also a shuttle bus to Antagnod and St. Jacques, though do check out the timescales as September is the end of the season.
Trail-wise, Ayas has everything from the casual stroll in the woods to hardcore alpinism, and as a valley I find it less pretentious than Courmayeur or less ghastly than Cervinia.
Another nice valley is Lys, with Gressoney as its main centre.