This is almost an impossible question to answer.
Both games do some things very well, and some not so well.
I believe that both are 'sim' games with flaws in different areas.
EA has more polish and
I like their controls more while 2K has deeper and more customizable franchise options.
Both have excellent presentation qualities but I enjoy EA's commentary better.
Download both demos and give both a whirl. Play 10 games of each and then see which one feels better or is more fun for you.
It really does depends on how you like your hockey games to play. But both will give you a pretty good simulation of NHL hockey.