Re-skinned versions of DKC > Reskinned versions of Banjo in flat levels.
Not even a big fan of Returns, DKC2 and Tropical Freeze are by far and away the best 2 in the series.
I still have no clue why you called them adventure games though. DK64 has more elements of being an adventure game then the DKC main line which are 100% pure 2D platformers.