This is a great time but honestly I don't see it as "the best" in the series personally.
Has some fun mini games, but several are reused from Mario Party 1. Half the maps are great, but the other half are bad. Item were introduced but you can only carry one so there's hardly any room for strategizing.

Mario Party 2 is good but was still at that phase of trying to perfect the formula that Mario Party 3 achieved later on.