There is more to enjoy than just the rain.
Enjoy the low 50 degree May days while the rest of the country is in the high 50's, 60's and 70's.
Enjoy the constant overcast skies starting in late september and lasting well into may.
Seattle has 230 cloudy days a year, with only Anchorage and 3 other NW cities having more.
Amazing Heroes is a fun store to browse. The prices are not amazing, but the selection on toys and games is solid.
Gameworks has a good number of newer racers and light gun games. Also a decent fighter section with a bunch of Net Citys and NNC's.
They are really lacking in the 90's arcade games, ie no Avp, Xmen, cave shmups, etc.
Actually, besides one of the raiden games I dont think they have any 90's shmups. Also, not many pins at all, but there are better places for that.
There are some other smaller places like Another Castle on Hwy 99 just north of Seattle, which has a decent little arcade with a game store attached, that are worth checking out.