There are 4 main ones that I know of: Malarone (Atovaquone/Proguanil), Doxycycline, Lariam (Mefloquine), and Chloroquine/Proguanil.
First, what areas will I be in? Let's check the CDC Map.
India (Jammu and Kashmir, Himachal Pradesh) (September): No malaria. It is too high altitude, or too cold, or something. However, I'll be on my way to J&K for the first couple days of September, and I'll dip into Punjab between Kashmir and HP I think, so it would probably not be unwise to be taking something anyway.
India (all the rest of it) (Oct-Dec): lots of malaria! And it's Chloroquine-resistant.
Indonesia (Borneo) (January): Well, yes, in rural areas.
Australia (January): Nope.
Iran (February): assuming I'm flying into Tehran and leaving to Turkey, should be no problem. The Northwest only has occasional malaria in March-November.
Caucasus countries (February): only after May or June.
Turkey (March): just about none, except the southeast part.
Bulgaria, Romania, Ukraine (Apr-May): none
Kazakhstan, Turkmenistan, Kyrgyzstan (Jun-Aug): none
Uzbekistan (Jun-Aug): "none reported in 2009"
Tajikistan (Jun-Aug): looks like there is some in the western parts.
Some other guides report even less malaria: Fit for Travel (UK)
Basically, I'll need about 4 months' worth of malaria drugs, for India and Indonesia.
Chloroquine/Proguanil: nah. Indian and Indonesian malaria is Chloroquine-resistant.
Malarone: I've used it before, had no side effects, all's well, it's okay for up to a year (or maybe 9-34 weeks? at least 6 months, anyway), etc. But it's expensive for a long stay: we're looking at maybe $800 for 120 tablets.
Doxycycline: is cheap: $30. You start taking it a couple days before and you take it for 4 weeks after you leave a malarial zone. You're not supposed to take it for... >4 months? >6 months? >2 years? No limit? Just about fine for me. Also can make you sun sensitive and/or your stomach upset.
Mefloquine: most of the ups and downs of Doxycycline, but with a few more side effects (vivid weird dreams- ooh! depression- ugh.) and a little more cost. Oh, and there's a little note about high altitude.
I wonder if my insurance would cover Malarone! Otherwise, Doxycycline sounds fine.
CDC short drug pros/cons lists
Consumer Reports in-depth drug guide