I'm a big fan of the Mario Kart franchise. I'm always excited to see a Mario Kart themed shirt on Shirt.Woot. You can still get this shirt on the reckoning wall for $15 at the time of this posting. The first one I saw was this one. If you're a fan like me, you love and hate the blue shell.
Nothing makes getting first place easier, or maintaining first place harder than the blue shell. The first blue shell appeared in Mario Kart 64. It was a plain spiney shell. It would break on walls and couldn't jump far gaps. It was the same way on Super Circuit for the Game Boy Advance.
Mario Kart Double Dash introduced the wing blue shell. The winged blue shell will hunt you down and annihilate the first place person. There is a catch however, it hits whoever is in first place at the time it is thrown. You can drop into third place and it still hit you. I noticed this on the Wii version. The explosion also takes out whoever is around you also.
I'm a big big fan of the Mario Kart series. My brother and I have played countless hours on the SNES and N64 versions and my wife and I play the Game Cube and Wii versions all the time. We actually went to the midnight release of Mario Kart Wii. I stared playing from the very beginning on SNES. I haven't played much of the DS game however. I'd have to say Mario 64 is my favorite. It fixed all of the rough edges that the original had. Super Circuit for GBA could use a serious remake with better controls to help it's bad reputation.