I like it because when I was a kid, we didn't have a lot of money, gen 3 was really the first time I could afford a console while people were still playing its games. I got Ruby and my best friend got Sapphire and we'd play pokemon together for hours on end. I guess I like gen 3 mostly because it brings back good memories like that. :)
It's not my favourite gen, though~ At the moment that's gen 5, which brought my favourite Pokemon, Scrafty~
Official Scrafty Of The Black And White Clan, Official Misdreavus of The BW 2 Boards. Official Lorelei of the BW 2 Boards.
I loved it because of the areas (Volcano and Desert FTW) and new pokemon. I didn't find the water annoying, just used Repel. The only thing that I hated was Zigzagoon being found everywhere in R/S, though Emerald fixed that.
Honestly I have no idea why Gen 3 is loved so much. I liked it, don't get me wrong, but there was something about it that didn't sit right with me. It reminded me of some new age take on the series. It was completely different than anything we have seen before in Pokemon. But mainly I feel it's what Hydreigoon posted.
Gen 1 was the original. Very plain and basic. Gen 2 had a quaint mysterious feel to the Region. With all its wooded villages and myths and legends. The region felt unique. Gen 3 I agree was a breath of fresh air. It had more of a "happy go lucky" feel to it than any region before or after. Maybe that's why. Water Routes agitated me beyond belief. (Sorry) Gen 4 had a great region with all the lakes (which were too small for my liking. Exploring wise), the mountain that looms right in the center. Your hike through the snow. But it still managed to be my least favorite Gen. Gen 5 did it right. The gen I loved the most. It rekindled my love for Pokemon. There are some areas I dread to travel through but still with the Pokemon, the music and the region. This is number 1 IMO. Gen 6 looks to be taking a play from the Sinnoh region but with even a bit more diversity between areas. I'm liking it.
Music, many of the pokemon(including my fave Medicham), the diversity of the region and good memories. I'm no fan of the Gen3 tilesets, but that's all, really. And that's why I like it. I love all gens tough, so yeah...
Too bad my Sapphire and Emerald both have no battery anymore so I can't rebattle trainers. Actually... Can that be fixed with the berry fix?