M47 Patton tanks standing in for Tiger IIs in the 1965 film "Battle of the Bulge"
Adding some opinion here since this has gotten a lot of attention: I think the M47s were excellent stand-ins. Firstly, the M47 conveys the power and size of the Tiger II well. Weighing in at almost 50 tons, the M47 is closer in weight to the Tiger 1 than it is to a Sherman (Granted, it's still 20 tons short of the Tiger 2).
It's also close in proportions. A lot of people have suggested that plywood mock ups should be added around other vehicles. Look at the movies that have done this though - Kelley's Heroes, White Tiger, Saving Private Ryan, Band of Brothers - they all look pretty bad. There's a reason the best ones (BoB and Saving Private Ryan) limit the amount of time you can see the Tigers and the angles of them. It's because you can't fake the proportions of the vehicle. The best vehicles these fakes could use were T-34s, but the T-34's forward turret and narrow body and tracks ruin the illusion, not to mention the sheer size discrepancy that results - the Tiger II is over 12 feet wide compared to a 9-foot-wide T-34. The M47's wide stance, long 90mm gun, sloped glacis, long and narrow turret mounted centrally, and large tracks make for a profile remarkably similar to the Tiger 2.
Another factor is the M47's V12 gasoline engine, which sounds much more like the Tiger's Maybach V12s than the diesel engines of a T-34 or any of the Sherman's engines.
The last thing about using the M47 is the sheer number that could be used. As anyone who has seen it knows, this movie has some truly impressive tank scenes because the Spanish military allowed them almost a brigade worth of operational tanks. It would be basically impossible, even if they had had a much higher budget, to acquire and convert that many tanks. This movie couldn't have existed any other way, and I think they pulled it off excellently.
