If going to Montepulciano, I'll suggest Crociani in the centre of Montepulciano, and Daviddi out near Stazione Montepulciano. Both smaller family operations and both normally fall under the radar of wine critics. Daviddi also typically offer back vintages of the riserva at modest prices for such 'museum' stock, and the wines from both age well. Crociani have a drop-in tasting room in the centre, but we felt they really appreciated that we booked an appointment, so I'd recommend that. Daviddi being out of town, will be very much better with an appointment (if not obligatory) and they were lovely towards us when we turned up wet from walking their, bringing us fresh towels to dry ourselves and also driving us to our next appointment! i.e. the sort of experience that can make smaller family operations so special / memorable.
I'll also throw in a suggestion of a larger place - Contucci. They are incredibly historic (over 1000 years), and pride themselves on focusing on direct sales, rather than cosying up to critics or major distributors.
