Well technically an AR-15 is not an assault rifle, it's a carbine rifle with a detachable box magazine and is single-shot only (semi-automatic). Personally I prefer the AK family of rifles, cheaper, very reliable and ammo is easy to find anywhere in the world. Well, maybe not in Britain of course.
Now this Sturmgewehr 44 is a true assault rifle. The name roughly translates into "Storm Rifle 44", it's selective fire, single-shot or full-auto. Useful in battle situations where cover fire is needed. Anyway, we can't just waltz into a gun shop and buy one, they don't make them anymore.