Maybe I oughta just flip a coin ?
The more info one gets the more indecisive / perplexed one becomes !
Pick a computer that some friend or associate of yours knows a lot about and can give you advice. It can be either windows or mac and a windows machine will be cheaper but require installing some (free) additional software to protect you from viruses and stuff like that.
Once that extra software is installed it is as safe as a mac because the software automatically updates to keep track of the latest viruses, etc.
But the most important thing is to have friends who can give you advice. If all else is equal I'd buy the same computer a knowledgeable friend has.