I think Libras and and Leos are the most talktive why because they are a postive sign they are very socialble I know a lot of people with those signs and they talk alot!
I think Libras and Geminis are rather loquacious. . XD but I LOVE listening to them talk.
Libras are so down to earth and real . . and so are geminis. Sagittarius and Leos are
very direct and straight forward . . and they like to talk as well XD. Soo overall Air and Fire signs.
Earth signs are very direct and straight forward . .
I'd say Gemini and Libra talk far too much. The most straightforward would tie between a Sag and a Scorp. The Sag because they don't feel they're being offensive by telling you the truth. A Scorp because they think you should be able to handle the truth or not ask for it.