I'd like both search functions (CTRL+F and the filter at the top) and sorting to ignore special characters, especially periods and diacritics. For example, Ōkami HD is now sorted last in my games list because there's a diacritic on the O, and I can't find Ōkami or République using the filter at the top because I'd have to enter it with diacritics exactly. This goes for the Q.U.B.E. and S.T.A.L.K.E.R. series too. Trademark symbols mess up the sorting between the Thief games I own on GOG and Steam too.

The CTRL+F search does ignore diacritics, but not periods.