Hip Hop. So diverse. What I see as Hip Hop is not what the next might think at all. However, there are some universal things that have made Hip Hop attractive. The roots it comes from. The classic boom bap sample driven simplicity of beats with mc's trying to encapsulate the mood or feeling behind the music. A good mc/rapper will show lyrical skills on a track through braggado rapping, story telling and imagery painting. It is a form of poetry of some sorts and thus wordplay, metaphors, concepts etc all play a vital part in being a good mc, and of course flow. It must be said, you won't find that in the more commercial streams except for a few artists. If you want to know what Hip Hop is truly about, The Roots is a good start as has been said but so is the whole 'golden era' of hip hop, the 90s. Artists like The Roots, Gang Starr, The Wu Tang Clan (and their solo works), Common, Fugees (from the score album), KRS One, Mos Def, Talib Kweli et al.
In the modern Hip Hop sounds, I like: Reks, Torae, Roc Marciano, Wildelux, Has Lo, Phonte (from the group Little Brother which I highly recommend) et al
In fact, you'd be well advised to check out Hectic's Hip Hop thread for references on albums to listen to. Hopefully you will understand what the real appeal behind the music is after that. You might still not be a fan ala Pogue but you will be able to understand why people love Hip Hop.