I have used Malarone on the last two tours of Africa for malaria prophylaxis.
It came onto the UK market around 1997 and I believe the US FDA have recently allowed it in the states. It has very low contra-indication rates and I have had no problem with it. It's a daily tablet, a combination of the old Chloroquin and a newer anti-viral that I cannot remember right now.
It is expensive (around two pounds a tablet in UK, US$6 here in HKG- someone's making a nice little earner on that one...) but it is probably the most effective and with the least side effects on the market.
I wouldn't touch Larium with a ten foot pole having seen its side effects in others. One boat skipper said he would not take people on board if they were using it because of his previous experiences of their strange reactions. It is a complete no-no for active pilots.
Doxycycline is OK for some areas but watch for the resistant strains which may be in your area. Anyway do you really want to keep taking a broad spectrum antibiotic all the time? Think about it.
Oh and if you are using a contraceptive pill with doxy you need to use another method of contraception as it frequently prevents the pill's absorbtion. Many medics forget to tell you that one...
QDM's recommended web site is excellent - try it first.