Amateur Radio Antenna It Is The Ultimate Source! What Is The Most Efficient 2-meter Antenna?

What is the most efficient 2-meter antenna? - amateur radio antenna it is the ultimate source!

Which antenna 2 meters in effect for an amateur radio operator in the barracks on base? Nothing beside the house, period. N antennas in the garden, without access to the attic. Basically, you can see from the outside. Pretty stringint standards. Find the best selection of my situation. Thank you in advance.