Irl, I love autumn and hate spring. But it's the total opposite in the game. They dulled down fall's beautiful colors into a mess of reddish brown. But spring is really pretty, and I don't have to deal with allergies in the game.
My town doesn't have much in the way of PWPs or flowers or any kind of path-making yet, so there isn't a particular season that compliments it. Personally, I like my town in summer. It reminds me of sunny days and long vacations.
My first town isn't built around a specific season, so it looks fine all year round. My second town, however, looks best in fall (bottom half is sweet olives and fruit/regular trees for fall) and winter (top half is holly and cedar trees for winter/Christmas)
I think fall towns are actually really pretty but my town would probably look ugly lol. I never thought about it since my town is pretty new but I started from December and am slowly tting back to real time. My town is currently in spring which I love! And I might stay in spring and make a dream address before continuing in.
Autumn is my favourite time of year in real life and ACNL so needless to say I do enjoy this time of year. However I gotta agree it does kinda make the towns look a lil ugly - mainly in my case though, since i'm using modern public work projects and the greys and silvers don't really blend in with the vibrant oranges. I think it can look nice especially if you set out to make a autumn themed town, but if not and i's something like a springtime town it doesn't really look that nice. My town Milk, before I deleted it and started again looked the best in winter though because of the white flowers and such so it looked majestic.
I used to hate it, but now that my new town's main fruit is oranges and I color coordinated the majority of my flowers to match, it doesn't look so horrid. It was so, so ugly when I had cherries and peaches, though.