I am becoming a huge fan of S3dCreator (see other posts for things about it in general). While it's $125, and probably the most expensive I can remember buying personally for software (yes, I've seen my company pay $25,000 for ONE licence for a program, but that's not me), but remember - we spent $2000 ish for these, and they're worthless without software!
The manual support generation works great. There are still bugs to be worked out, but the positive thing is you actually get REAL feedback from the creators who actually add feature requests in a reasonable amount of time! (Not naming names, but opposite of what most of us have experienced with our printers).
Specifically you can define specific support areas, create manual pillars, and then add more or less support automatically. Additionally, you can set different heights where you want support printed; I did a model where I wanted support just for the first 4 mm and then wanted the rest of the flask to stay hollow, and it worked great! You can define how ever many transitions of that that you may want.
I will absolutely admit it is hard to get over the price tag, but it was just as hard for me to get over the price tag of buying $1 apps for my iPad. If you don't pay some money, you really can't take full advantage of things.
I think the actual feedback and implementation of suggestions/wants could really be worth it. Feel free to email/message/repost if you want some examples from it. They do have a free trial for 2 weeks if you email them. (And check out my and other posts for other features).
I did try KiSS, and it did ok, but it's really not on the same level as this software.