It's like the best song the Rolling Stones or U2 ever wrote compared to the best symphony Mozart ever composed. They're all amazing in their subjective categories but different enough where direct comparisons are rather trite, IMO.
Of this we agree. You seem to negate this argument later in your post by directly comparing Watchmen and War and Peace anyway, but I'll withdraw.
I haven't even read either, anyway.
And even if I did, I've read so few comic books that I wouldn't have much cultural context beyond what I've been able to glean from wikipedia on the subject anyway.