It's hard to rate and compare people in something that's been on as long as Jeopardy, just as it's tough to compare, say, Shoeless Joe Jackson and Ken Griffey, Jr; different time, different game.
Who's better; the Fleming run champ who wins five games and $7,500, or someone from this year who wins 10 games and $150,000?
If you were to look at the raw numbers; he's winning with about $35,000 a show, depending on various factors. How many people in history won even five games, each at $17,500? Not a whole lot. Bob Blake's average is a dollar short, and there are precious few $80,000 and $90,000 winners, under the old rules.
You'll never get a definitive answer out of me, but Jennings is top five, maybe top three of Jeopardy players of the current run. Easy.
-Travis