Just getting into some
slide myself. There's a lot of tunings, some of which you're going to spend a lot of time trying to find a second song to play.
Open G- D G D G B D seems to be a good one to start with- you can find quite a few songs and if you think in terms of the basic I, IV, V: open G, of course being the I, it's easy to get something out of it that sounds OK.
Of course, I agree, that after you've put so much effort into standard tuning you're opening a whole new can of worms, and I really like Kurt's take on dropped D tuning - I think it's 'the beans', but I do enjoy the sound of an alternative tuning and if you play around with it a bit you can get it to sound pretty good without having to turn your world upside down.
If you're a blues fan check out some Muddy Waters, or just play around with it