Honestly though, and I know this is a minority opinion, I think FFIV-XI are all great games for their own reasons.
Christopher, if you want a Final Fantasy to play after X I highly suggest going with either VI, VII, IX, or even Chrono Trigger...which isn't a Final Fantasy at all but very similar to it. Those are all the titles I suggest to anyone interested in getting into FF. I'd normally suggest X, but alas, you're playing that now. FFIV remake comes out in 2 months. I'd suggest it, but I'm not sure how you feel about oldschool rpgs, which is why I'd suggest playing IX (which is oldschool in spirit) and VI (which is oldschool but still very modern in terms of story telling and character customization) first.
4. Final Fantasy IX - This is understandably one of the most hated on FF's next to FFVIII for a few reasons: 1. The final boss comes out of nowhere, 2. THe villian was mostly weaksauce and boring, 3. The battle system was sloooow 4. the characters felt like filler aside from a few. It's not my favorite, but it's still one of the best rpgs of the psx era. The light hearted take really appeals to me, and while the battle system is slow as fuck the AP and Weapon/Armor skill system is nothing but addicting. Also, Vivi is the best character in the series and Steiner is THE best damn comedy relief. Also, the game has the best side quests in the series bar none.
I think that when it comes to FF, people get too emotional and bogged down with what their favorites in the series are instead of appreciating what the current FF is doing right then and there. I think there's something to appreciate in all Final Fantasy's FFIV-XI completely.