really tough to compare whats the best i think though in the 60s 70s marvel was really on the ball they broke a lot of rules especially with the spiderman gwen stacy story line virtually unheard off to kill of a heroine x men did that 2 wit hthe dark phonix saga killing jean grey allthough no permently. 60s 70s dc i found a bit camp allthough good 4 the time lacked depth. 80s i would say both were even with frank millers batman year one made the dark knight really gritty followed by the dark knight return and the dark knight strikes back. also the killing joke became one of the best joker stories ever told exploreing the jokers origin. arkham asylum a serious house ona serious earth showed the most psycological batman story. marvel became darker as well in the sin eater arc spiderman trying to find a serial killer responisble for the death of jean de wolf later found out to be the jeans lover also show spiderman at his darkest nearly beating him to death untill he is intrivened by daredevil. another infamous arc is kravens last hunt where spiderman is burried alive and kraven comits suicide. dc gained mormentul in the late 80s thanks to the watchmen basicly the most adult super hero comic at that time excellent story telling with lots of thing u descover re reading it again. 90s marvel had took a risk that kinda messed up the spiderman story line the clone saga going back ward to issues 149 150 thsi story line i found was to elaborate and confuseing. then they bring back norman osbourn who met his demise on the tail end of his glider they really screwed it up allthough the web of death arc i would say was the best due to the final issue of it the death of doc ock who they bring back again. when a characters dead leave it at that unless u can think of a good reason to do it most of the time its kinda phoney. the x men storylines were good though. dc i find really got the sorylines going well 4 the dark knight the long halloween excellent example of great suspence and writing. 2000 i think marvel went overboard with these complex storys civil war secret invasion turning iron man into the villian allthough i never liked iron man liek a wanna be bruce wayne tony stark seems. dc coudl be acussed of the smae thing with the recent story lines killing off batman and replaceing him with **** grayson allthough it wa handdled a bit better than the brand new day story line. mj in that shows she got more guts than peter he would give up his marage to her to save aunt mays life am going thats insane am going should have been left dead in amazing spiderman 400. marvel i felt has declined a bit allthough i did liek the ultimite universe storys. i find that dc that through the majority has more consisticy wit hthere story lines as much as i like spider man stuff soem storys though the 90s and 2000 are not up to calibar.
so after this lenghly debate i would say dc overall but marvels not to far behind.