What is the best toot to use for cutting a finished piece of aluminum sheet? Electric Shears, Nibbler, other?

The tech data on the aluminum states it is .02 thick. I need to cut very straight lines on this finished piece of aluminum and am not sure what type of tool to use to cut it. I could go with electronic shears or an electronic nibbler but have not used either of these tools before. Any help would be greatly appreciated.