Imperial Settlers VS Five Tribes VS Small World

So.. I've been torn between buying Imperial Settlers and Five Tribes 4 a while. I like that Imperial Settlers seems a little lighter to teach my not so gamer friends, but I've really really enjoyed a game of Five Tribes, though I noticed how AP can be a problem. I've been making pros and cons (like how Five Tribes has more beautiful artwork, how Imperial Settlers I can play solo, but the egyptians win more often) and then.. I watched Small World being played on Tabletop.. and I also liked it a lot!, so here I am, watching reviews... trying to figure out which would be best to buy. Any comments?