The Gallardo got an engine of its own, the all new Lamborghini V10. It's actually only the third engine made by the famed Italian exotic car maker in its history.
With such a low price compared to the other Lamborghini option, the Gallarado has sold remarkably well. Over 5,000 of them have been produced, the most of any Lamborghini model ever. The Gallardo has only been sold since 2003, so the annual sales numbers blow any other Lamborghini sales numbers out of the water.
The Gallardo comes in two body styles, the 2 door coupe and 2 door spider. They are all 4 wheel drive, and the transmission is a 6 speed manual or an optional 6 speed automatic. The automatic has not been a common option on Lamborghinis, but this car was obviously made to appeal to the masses who might not now how to drive a manual transmission, especially when it's attached to a V10 engine.
The Gallardo is more driveable than the larger Murcielago, and provides better visibility in the rear. It could probably beat its big brother on a road track with lots of turns.
The Gallardo was the first Lamborghini car in decades to not have the popular scissor doors. That has disappointed some fans, but it also makes it less showy, which makes it more desireable among the more subdued and refined upper class.
You can find plenty of these in collector car listings if you don't feel like paying full price for a new Gallardo at a Lambo dealership. You'll also find them listed on eBay at a steep discount. It's the first place I'd look.