The Posse is always keeping an eye out for the greatest sandwiches offered on the Texas BBQ trail. Such was the case the first time we saw the massive $2.75 chopped beef sandwich at Meshack’s BBQ in Garland, the BBQ Po Boy at Loco Coyote Grill in Glen Rose or my favorite, the Brother-in-Law sandwich at Stanley’s Famous Pit Bar-B-Q in Tyler. Well, it looks like there’s another contender for the BBQ sandwich elite, the Tipsy Texan at Franklin Barbecue in Austin. Seriouseats.com blogger Carrie Vasios sums up the Tipsy Texan this way, “This sandwich tastes like everything that is…