The classics are a good way of getting to the backbone of storytelling ability, and some of the main themes and ideas that come out in the history of writing. It's also often a good way to get a slice of history and the social constructs and behaviors at the time, or analysis on the human condition, etc, etc. You don't have to like them, not at all. But they should be studied and read just to understand more about literature and the world itself.

Personally, I think Mark Twain kicks incredible amounts of ass with his writing, as well as other classic authors. Oscar Wilde's plays? Also a favorite of mine. But I think Nathaniel Hawthorne can suck a gigantic cock, and the same for Edith Wharton for writing Ethan Frome. The classics are important, but not always likable. It's important to note their influence, their style, etc, etc. They're classics for a reason, after all.

But you can still have your classics and read your fantasy, too. Odds are high that a fantasy novel will be more immediately gripping and entertaining, but that a classic novel will have more to dig into. Neither invalidates the other.

Just don't ever read only one kind of book. Otherwise, you end up like the guys in the busty anime nurse t-shirts walking into Barnes and Nobles, getting excited about the Video Game novel adaptations, and when questioned by a gal pal in tow with 'You read?', responding with a 'CHFFH, YEAH, THIS stuff.'

There's more than just classics or sci-fi/fantasy out there, after all.