most LV mono and epi in the classic shapes
chanel quilted bags in the squarish shapes
hermes obviously
YSL muse
kate spade nylon and boarskin bags for the most part
I'd say most any quality bag that isn't super trendy. Most Chanel, LV (Damier, Mono and Epi), Hermes and Tod's could definitely be carried for years to come.
For me its the Spy. I saw it and loved it, and was looking for it in Topshop until I found out that it was from Fendi and it was an IT bag called the Spy! I'll always love my dark chocolate Spy. And I think it will always be IN.