How to play US/JP games on an European SNES? What is best way - mod, adapter etc?
I'm more PlayStation gamer/collector, but I just bought my first SNES
Thank you for your advice!

I use an adapter. It has two slots. One for a PAL SNES game to bypass the lockout chip. You can find them fairly cheap on Ebay or maybe someone from NA has one for sale.

EDIT:

http://www.ebay.de/itm/SNES-Super...

Something like this. Though I do think it is a bit pricey.

DMG, danke schön
I read, that those adapters works only with older SNES games (pre 1993)?
P.S does Super Game Boy work with every region game or not?

Yes, I believe that the Super Game Boy doesn't care where the GB game is from. Not entirely sure though.

Another option to play NTSC SNES games is to mod your console. A few methods can be found here:

http://www.mmmonkey.co.uk/console... <- This one is fairly simple and the one I'd recommend
http://www.mmmonkey.co.uk/console... <- Bit harder but means you don't need switches. I think some games don't like this method though.

Thank you!
Aren't the American cartridges a little wider, so they don't fit to EU SNES?

Yes, they are wider, so you'd have to use the adapter. And to confirm, Gameboy carts aren't region coded, so you can use them on any Super GameBoy.

Could you use a PAL game genie as an adapter? Might help with some region lock outs too, I know certain games throw errors.

Are boards of these cartridges same size/shape?

I've got a pal WORMS cart here, matched the pcb against an american game pcb and the pinout / form factor of the pcb is the same cross region, however there's a different lock out chip. I'm taking a shot in the dark that the GG has a lockout made for your PAL snes and will cover up the fact you're using NTSC games and allow for the difference in cartridge shape as it sticks up out of the system removing the size / shape factor from the equation. I could be completely wrong but I've heard of people getting around the physical lock out this way in the past.

Wrong topic. Sorry, don't really know! 

My cartridge slot is sanded at each side to make NTSC carts fit in it. Mine just has the 50/60hz switch and I've yet to encounter a game that doesn't work. I'd take some pictures but I'm not at home until Tuesday so it'll probably be too late by then.

GhostNinja, take your time - at the moment I try figured out best solution.

Sorry, I've been pretty lazy with these pictures. Here's my SNES. Ignore the controller, I couldn't be bothered to move it because it's a pain to get it to stay anywhere else without sliding off. The thing circled in red on the second picture is the 50/60Hz switch.

Is there anywhere to do the opposite of this? you know play PAL snes carts on a US SNES or japanese carts? pm me with any info. thanks

GhostNinja, nice work - thank you