A good site for checking the "strains" of Malaria you need to be guarded against is an American military website, if you can find that, give it a looksie. Good suggestions on it.
They all have problems. I did a fair bit of research after I was prescribed Larium, and whilst it's extremely convenient (take 1 tablet once a week...) it has a fair load of horror stories. I found the first time I took it, it made me feel really sick and ill and weird, plus it makes dreams very... I dunno. I would say "vivid" but it's more than vivid, it's like something changes, and you actually believe the dream until you wake up, whilst at the same time not remembering or understanding it. It's really not very nice, but I guess with the good dreams it was ok, and I got used to it.
I was prescribed Larium in Australia (before I left for Asia), to last me in Thailand, Cambodia and Nepal, and to be honest, I was mainly in more urban/populated areas cleansed of malaria generally, in SE Asia, and in Nepal once you get up into any sort of elevation the malaria risk is ziltch. I saw bugger all mossies in Nepal, and stopped taking them anyway (although I carried on for 2 weeks afterwards, incase it was in my body, and then said fuck it!)
As for deoxycycline, one of the main benefits is it's cheappppp, especially compared to some others. It does however need to be taken daily, it can affect dreams and make people feel ill etc etc.
There's malarone which my friend took, and is the one which can cause horrible ulcers, but that seems to be the worst side effects; generally there are way fewer problems than some of the others (it does have to be taken daily though), and various health organisations seem to be bigging it up at the moment. It's expensive too, which is another factor.
It does depend on where you're travelling to (Siem Reap, Phnom Penn, Hanoi etc, or tiny villages in Cambodia n north Thailand), and the risk you're prepared to take, to be honest. The season you're in a country can greatly affect the number of mossies, and thus your chance of getting nipped, which you want to avoid anyway! Get some good DEET and cover up etc etc. There are other tropical nasties aside from malaria worth worrying about, which i'm sure you're aware of
Out of the people I met in Cambodia, I would say a fair few (perhaps a majority?

) took the risk and didn't bother with anti-malarials. It's definitely a
risk, however if you have good insurance, worst comes to the worst you'll be evacuated (if that's an option). The guy running the hotel/hostel I stayed at in Bangkok was very clued up about malarial risk, mossies and just general travel, and his view was (which he alleges is a view shared by many in the region) that taking
no anti-malarials
can make sense. he argued this because often the medication can give similar symptoms, and if it fails (which it can do), then you can mistake early on set of malaria for side-effects from the drugs. He got dengue fever in Cambodia, and was far more worried about things such as that than Malaria, seeing as he could have died... of course, anti malarials dont work against that anyway.
Mmm sorry for this ramble anyhoo! You are travelling to this region though.... and I presume you'll be going when it's moving out of the wet season. I think if I went back, I would
consider not taking any anti-malarials in Cambodia/Thailand/Vietnam/Laos etc, unless I was in very affected areas for weeks at a time. Then again, i am young and foolish. I did meet a fair few people who'd been travelling around the region for years though, and had never had any malarial problems, then just made sure to minimise bites as much as possible, and if any potential symptoms were popping up, to get help ASAP.
Good luck.