Walthers offers great variety of kits that cover a wide range of structures.
HOWEVER I have found Walthers kits well...to be lacking in assembly quality. Warped pieces, and clear "glass" acetane which has scratches and mold lines running down the middle are my main gripes.
My vote goes to Kibri, City Classic, DPM, and Art Deco. Each of them assemble very nicely, and the detail work is outstanding. Kibri kits also seperate nicely from the spru. You have no idea how much you'll appreciate it until you put one together.
I've put together about ~32 kits and counting. (Including core built pullmans)
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum
Chip
Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.
Modeling the B&M Railroad during the transition era in Lowell, MA
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
It takes an iron man to play with a toy iron horse.