DAITER'S and NORTOWN both carry them...and they have become my 'new' favourites (half sours, that is ). I was a big fan of Bubbies Pickles, available at Fiesta Farms (and a few other places) but once I discovered Nathan's it was and is game over!!!
I recently saw Nathan's half-sours at the New Yorker Deli on Bay and Bloor. They also had Nathan's horseradish pickles. Their regular dills are my faves, but I'm not sure what brand they are. Putters maybe?