Points per game
Hull: 1, 1, 2, 2, 2, 3, 4, 4, 5, 5, 7, 9
Ovechkin: 1, 1, 1, 5, 5, 8, 9, 9
Goals per game
Hull: 1, 1, 1, 1, 1, 1, 1, 1, 3, 4, 4, 6, 6
Ovechkin: 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 5, 5, 6, 8, 9
Just looking at very high-end 'best' finishes (i.e., ignoring historical context, etc.), Hull actually is slightly better than Ovechkin, since they match up in seasons as #1 in goals per game (8 each), and Hull is slightly better in points per game.
It's of course in longevity of high-end seasons that Ovechkin pulls ahead, as he has (outside of #1 GPG years) eight more high-end seasonal finishes to Hull's five. However, Ovechkin has played four (and counting) more full NHL seasons than Hull in his career, so that might slighly lower Ovechkin's edge (i.e., if we look at each player's first 15 seasons).
I don't think either guy has a better argument in NHL playoffs, do they? Seems very comparable. Both guys won one Cup, with several team disappointments along the way. Maybe Ovechkin has the edge because he was his team's top guy when he won the Cup, whereas Hull (arguably) wasn't even at his prime yet.
Overall, I give Ovechkin a slight edge over Hull for a few reasons:
i) As primes are about even, Ovechkin then has more elite seasons in the NHL than Hull (this might not be Hull's "fault" so to speak, as he left the NHL to make money that is still small potatoes compared to Ovi's salary, but nevertheless he left).
ii) Ovechkin has more raw #1 goals finishes than Hull.
iii) Ovechkin carried the offensive load for his team more (Hull could lean more on Mikita, a four-time scoring champion and League MVP)
iii) Hull's team was more disappointing, which suggests he moved the needle a bit less.
But I wouldn't argue too much with anyone preferring Hull. Hull and Ovechkin are like different-era versions of each other, just like Beliveau and Crosby are. (McDavid is like Orr if he were a forward.)