How is Ryan laughable? 7 career no hitters and by far the most Ks of all-time. Glavine is like the third winningest lefty and probably the most underrated guy on the list. I'm not saying he is number 1 I just need enough guys to make out a full 15.
Most K's of all time? Wicked nice... Except that if you do the percentage difference between him and K man number two, and BB man #1 (him) and #2, his lead over the #2 BB man is a good deal larger. Not so hot.
7 career no hitters? How about over his entire career? On any given night he was no place near Clemens, Koufax, Gibson, Maddux. On average he was 11% better then the average pitcher in the given year pitched (ERA+ adjusted for park, and per year is the single most helpful way to look at a pitcher - unless you count the stats that are associated like DERA and NERA.
Pedro is 57% better then average
Mussina 22% (twice as good as Ryan)
Lowe 19% (har har)
as long lasting physical freak he's in the top 5, too bad that isn't the same as pitching.