I've just gone over the list of all taigas I have watched, and that goes back to mid-80s, but there wasn't a single one I remembered as happy... Naotora may be your best bet, actually? The story focuses on a party that does not ultimately end up on the losing side, is mostly free of tragic hero worship (main reason I often prefer taigas sets in 16th century to 19th century ones...), and there's enough humor to counter the sads. Sure, there were a few crushing deaths along the way, but on the whole this series struck me as more positive than most.