Stainless steel is not so great, depending what it's next to. I put stainless steel screws in some temporary repairs using Galvanised steel plates on a wooden canal boat and when I came to replace them and the plates with real new wood the screws had become pink pins!
Also, used some stainless self tappers to hold new aluminium gutter sections round the engine bay on my Reliant Fox van. All looked lovely, until the first morning of dew and white powder appeared around the junction twixt the twain. I had to keep it regularly greased. Brass and stainless not great either as the stainless has stuff in it that the copper doesn't like. The Galvanic table is a right pain. Aluminium and brass also a no-no.
Cheers,
Martin