For Beef on Weck, I agree with everyone about Schwabel's in West Seneca, though I haven't been there since they changed hands.
Forget Anchor Bar for beef-on-weck, last time I was there, the meager-beef sandwich was dry and their horseradish came in a little plastic take-out envelope. Yuck!!!!
I'm surprised that no one mentioned Ulrich's Tavern, downtown on Ellicott and Virginia, for a fish-fry. Nice big piece with crispy batter. Ulrich's is the oldest continually-running tavern in Buffalo and has a German-Irish ancestry, so they do good german potato salad or spaetzle as sides, which I would reccomend. Very good collection of local and craft-beers on tap, too.
My wife and I are regulars.
Schwabel's in West Seneca, is good.. though they recently changed ownership. Plenty of other very good beef on weck joints in WNY..I like Charlie The Butcher..who has a small stand close to the airport(backside near Prior Aviation.)..and he's inside the Wegmans supermarket on Alberta Drive--next to Blvd. Mall. Another is Brennans Bowery Bar, located at the Main/Transit intersection in a strip mall. They pile on the beef and the horseradish has a good kick, too. Happy eating..and welcome back !
You'll hear a lot of good for Schwabel's but I really like BarBill in East Aurora. Anchor Bar has become a tourist trap. BarBill has excellent wings too.
It's not like it was - a good beef on weck in just about every corner bar. Same thing with Friday fish frys. Even finding good weck rolls has become problematic - Charlie the Butcher may have good beef but the roll sucks. I know you won't be disappointed at BarBill!