My favourite was the giant welding torch (Weldar). I really want a Final Boss in these games to have more challenge (Hag 1 was hard, but not when you knew what to do, even in Replay) and to have different phases that are like each different boss in the game.
Banjo Tooie for N64 (second in the Banjo-Kazooie series). Its been my fave for about 5 years. I got the new Banjo Kazooie hgame on X-Box 360, but I prefer Tooie.