Well, unlike a lot of Pokémon nerds, I'm a story junkie and like character development. While I like competitive battling (I'm even an Elite Four member in my school's Pokémon League), I enjoyed Hoenn's story and characters.
Brendan (in his Emerald uniform) is my favorite playable character. Who else has an awesome hat that looks like white hair? I mean, compare him to Lucas. Lucas had a beret and a scarf. I totally didn't feel gay playing as him. /sarcasm And May. Her timidness and her slowly becoming more comfortable around Brendan is excellent character development (especially for a "kid's" game). The same applies to Wally.
Need I mention you have to stop TWO villainous teams? Oh, and guess what! SPOILER ALERT: You don't stop them in time. While you do stop them eventually, you watch the world dry out and/or flood (depends on the game).
And your character actually has a Dad this time. A Dad! Finally, a father that DOESN'T abandon his wife and kid/children (again, depends on game).
Don't even get me started on the landscape and Secret Bases! And need I mention the introduction of Mudkip? Flygon? Salamence? Etc.?
And Emerald expanded on all of this! The Sinnoh/Johto Battle Frontier is a JOKE compared to Hoenn's. The ability to get the entire Weather Trio was nice. Same with getting BOTH fossils (and a new tower and cave to obtain them in)! Although the Trainer Tower was a rather pointless addition, I warmly welcome any bonus content. And they replaced the "tall" font with the one from FireRed and LeafGreen (which is nice since the "tall" font was awkward).
If you look at the series with the fun perspective instead of a competitive one, you will find that the Hoenn games (more specifically, Emerald Version) are magnificent! ~STBE