Just because you got lots more channels with the old analog broadcasts, it doesn't mean you can get that many with digital. With analog, you could get a watchable picture from a distant station even if it was weak. It just meant the picture might be a little snowy or fuzzy. It's a lot different with digital.
Digital reception is pretty much "all or nothing". That means either you get the channel or you get a "no signal" message. If the signal from the antenna is too weak, unlike the analog fuzzy picture there is nothing at all.
10 channels isn't a bad number, by the way. A lot of people are finding they get far fewer than that, even no channels at all. It all depends on your distance and direction from the station. If you go to www.antennaweb.org
and click on "choose an antenna", they can help you determine what stations are on the air around your area, how far away they are, and what type of antenna would be required.
The "best" antenna is the one that gets the strongest signal from the most stations. For your specific location, this might be as simple as amplified rabbit-ears. Or it might mean a large rooftop antenna that you can turn to point right at the station. That option may not be available to an apartment dweller. You might just already have the best you'll get if you're getting 10 channels already.