Love this thread! I have many in this category unfortunately. The ones that stand out:
Balenciaga City and all other bags in that line - love the edgy look but just didn't work for me. Kept my 2004 Twiggy though - amazing leather and I wanted to have one oldie but goodie Bal relic.
LV multi-color Speedy...was never comfortable with the flashy look...just not me...sold while they were still popular.
Mulberry Bayswater. Too heavy and flap bags don't work for me. Sold.
Proenza Schouler PS1. Again, flap opening was no good for me. Trying to open/close it annoyed me. Sold.
I think Mulberry, especially the Alexa and Proenza Schouler, again especially the satchel-like one (can never remember which is PS1 or 11) are great, but had a phase and now they look a bit dated imo.. And yes to Bayswater being rather heavy!