I played Wild World daily for nearly 3 straight years from 2005 to 2008, and I've been playing New Leaf from launch until today (doesn't matter when you read this, I'm still playing that daily, so it's always today). I can tell some of the things I liked about each. Wild World, first was portable. I had Animal Crossing on the Game Cube, and Wild World allowed me to take my town with me, so I never missed an event like I would in AC (I'm also a devout legit gamer- no time travel, if I miss it, just like in real life, I missed it). Second, it used the touch screen to run, talk to animals, etc. It had improvements over the original, like touching the animal who would either wave if you were friends, or scowl/snark if you weren't. Some other reasons I like it? The acorn festival was fun (got many a mushroom furniture that way). Since you shared a house, it was VERY easy to pay off the loan if you had 4 players living in it as I did. The attic wasn't just for saving, people forget that you could change your bed too- I put a nice large modern bed for me, the king! The phone also allowed you to change the clock, should you want to time travel back and forth I guess. The dialog in Wild World made me feel more connected to these animals. Marina talking about Mopina, the villagers talking about the Happy Room Academy points their house received (especially if you give them something that completes a set), and the villager pictures in your house give you a bazillion points, because it didn't matter if they lived there or not!
Now, New Leaf came after Wild World, and is a mix of the original, Wild World and City Folk. On the original, they added the island back (and some mini-games, making it more fun than the original I think). Wild World's layout is the background they used for New Leaf- ie no cliffs in the middle of town like the original and City Folk where you had to find that stupid ramp to reach the other half of town. They cleaned up the graphics in New Leaf too, making the trees and villagers look better (not to mention also in 3D). They kept the downtown city aspect from City Folk with Main Street. However, unlike City Folk, the Main Street population is populated only from your villagers, past and/or present. Obviously, since New Leaf is the most recent, it has the most items available, as now you can do pants, shirts, shoes, even socks, hats.
They took a lot of the good points from the previous 3, and meshed them all together, added a few new features, some little things too like footprints in the sand/dirt that changes depending on what you're wearing or not wearing, to create what is probably the best Animal Crossing yet. It'd be 100% perfect I think if they would have kept the speaking option City Folk had. Wii Speak was great, and the 3DS has a built-in microphone. To sum this all up, don't really compare New Leaf to Wild World, it's like comparing Super Mario Brothers to Super Mario 64, obviously the following games are going to be more technologically advanced, and have more features that weren't available years earlier. However, Wild World did lay the groundwork for New Leaf, so it can't be ignored either. At least in Wild World, thanks to having 3 other characters as well, all 8 of my villagers are "locked" as long as none of them ever talks to any of the villagers (or the villagers for which they didn't fulfill the task). I can put Wild World away for 10 years, pick it up, and none of the villagers will be gone, or in boxes! Not the case in New Leaf sadly.
