As I mentioned quite a while ago, I went to SELWG and bought some Peter Pig 15mm figures after playing in a demo game of AK47 Republic. When I got home I couldn't resist playing with the new toys I had bought, and I started sorting them out and basing them up.
Though in the latter case I've gone off message, as I wasn't totally convinced by the basing in the rules. So I've chosen to base professionals as per AK47, but I have increase the frontage for regulars by 10mm and 20mm for militia, which will allow me to put more figures on each base.
Why I hear you ask? Rhetorically that is, because I haven't got spy-ware that allows me to hear anything you say, but you can always leave a comment.
Well, for me, when using miniatures they must represent something more than just being a pretty counter or game token. I'm a firm believer that if you are not encoding information for the game into the figures, and the terrain, then you are missing out on the benefits of using figures in a three dimensional landscape. AFAIC you might as well use counters for your game.
Your mileage may vary on this one, but it's a thing for me that adds to the visual and textural experience of playing a game, which for me adds more than the sum of its parts.