Ajanta Caves

The Ajanta caves are similar to the Ellora caves, but in my mind are a lot less fun. They're also temples built into caves in a hill. The setting is slightly more impressive, since the Ajunta caves are in a canyon, while the Ellora caves just are on a (seemed to me) random hill. Also, the Ajunta caves are closer to and significantly easier for get to from Delhi. In contrast, pretty much the only way to get to Ellora involves going through Bombay, or through Ajunta.

That said, I still like Ellora better. There is significantly more tourism built up around Ajunta, with the accompanying restrictions, restraint ropes, and guards saying "no!" Also, the big draw for Ellora is stone carvings, while the draw for Ajunta is cave paintings. The paintings are poorly illuminated in an attempt to preserve them. Sadly, this means they're also difficult to see. Also, the Ajunta caves are all Jain, which means they they all follow one of two patterns (from what I could see) and so got a little repetitive.

So, if you had to choose, go see Ellora. If you're pressed for time, go see Ajunta. If you have time, go see both.