I never pick Conker's Bad Fur Day, even though its script was fun and its level design interesting, because the platforming and combat is very hardcore. I also think that, when Rare were bought by Microsoft, they should have released Twelve Tales as a standalone game.
In some ways, I admire how such a convoluted idea as backtracking with 5 characters in DK64 made such a mysteriously epic feeling game.
However, for a combination of enjoyment and novelty, staying true to classic platform game staples such as ice world, haunted house, underwater, I'll go for Banjo Kazooie although Conker is probably the most entertaining game. I never got in to Tooie - it felt like an adventure game (rather than a platformer) in disguise. But that's a thing with the Banjo series- as if taking a cue from Mario, codename Project Dream always seems to want to dream up some new gameplay mechanics.