The only big/real air show in Germany will be ILA 2008 in Berlin, but normally it's in May. It's more of a commercial / trade show. Switzerland isn't really known for air shows either, only the AXALP exercise in October. I don't know about Spain, there are always some beach air shows, I prefer shows at military air bases though. I'll get back to you here when more is known for the 2008 season. The RNLAF open days are pretty big, normally in mid June, this time at Leeuwarden in the north.
I'd focus on RIAT for now though. With some good weather, it will surely be the show of your life so far. I am still working on my photos from the show this year.
But if you like warbirds, go for Duxford - the museum and the Flying Legends air show.
There's no Paris Le Bourget or MAKS in 2008.