Right now I'm obsessed with Ultimate Sims, so all my legacies and genetacies are based on that. As far as generations go, I always aim for at least 10 for a legacy or 104 with a genetacy - but usually I have computer issues or something before that hits! All of my PlumTree trees can be found on my thread, the link is in my signature. There are two posts with lists, the newer one and the older one if you want to see both. I think I still have those old saves - but don't quote me on that, thanks to technology snafus' here recently. I try to only have one kid per legacy these days, and that makes picking heir easy! Unless it's twins, then I do a poll, and the other one heads off into the wild after college/adult birthday. MCCC can take care of them, unless I'm really attached. Genetacies they all have to be played, so the two spares (or more) are always played rotation style.
I think that about covers it lol.