1. Star Wars — 6 movies
There were the original trilogy (films 4-6) and the prequel trilogy (1-3) and you could event try to count the Holiday Special, but at most that would give you 7.
2. Michael Jordan — 6 championship rings
His Airness went three-peat twice with a two year hiatus playing baseball after the loss of his father.
3. Nirvana — 6 years
They recorded together for 6 years between 1988-1994 ending with the untimely death of lead singer Kurt Cobain from a self-inflicted gun shot wound.
4. Harry Potter— 7 books
There are a total 7 books to date and we can most likely rely on a seventh film (currently at 6).
5. Freddy Kruger — 8 movies
There were eight movies made between 1984 and 2003 (including Freddy vs. Jason). Note: They are remaking the original Nightmare starring Jackie Earle Haley.
6. George Foreman — 76-5
The man with his name on the grill only lost 5 fights between 1969 and 1997, losing his first fight to Muhammad Ali at the "Rumble in the Jungle." Overall he won 76 fights; with 68 by way of knock out.