I started with DBZ, too. I moved on to whatever was on CN - Gundam Wing, Outlaw Star, Hack, Cowboy Bebop, Rurouni Kenshin, (bought it to see all of it), Inuyasha (bought half the series, then found out about downloading it).
From a watching stand point and because you listed you like magic, action, and suspense, I would recommend Inuyasha. It has those plus humor, romance, great bad guys and of course the mysterious Sesshoumaru. But, with any series you really need to watch it from the beginning.
From your list, I can't say on Naruto (I'm going to watch it soon), but I would have to go with Rurouni Kenshin only if you include the OVAs and watch them in the order of the story...trust and betrayal OVA then the series, then that last OVAs. Escaflowne and YuYuHakusho are good, too, but I have to admit I haven't watched the ending of YYH yet (but I do have to series, now)
Actually Tabbykat had a great breakdown on a list of series that are all good (at least the ones I've seen which was about 80% of them).
Good luck choosing a series or better yet, do what I do and watch as many as you can.
