Aztec surely. I liked it so much that my maiden video had this map in the backdrop. Being a hardcore terro I used to find Aztec the most challenging arena. Even the most amateur Counter-terros (CTs) used to grab a sniper and always aim at the doors and the bridge. One wrong step and your head would be knocked off. Imagine a team of 10-15 each and half of the CTs defending with snipers not to mention people like Tango Charlie (Pilli) and Stealth (Kulin) rushing out of the doors and carrying out a massacre of unsuspecting terrors from behind. Getting killed by them was the most frustrating part.
Nevertheless, there was hardly a time when the spirit of the terros receded. I can still recall the pre-round strategies forged to combat the unfair advantage that the CTs possessed. "Let's storm the gate", "Storm the bridge", "Rush through the water", "Hold back".....n all. This for me was the funniest part. People taking charge used to falter when needed. Within seconds the snipers would take out half of the terrors. The only way to win was to pray for the CTs to charge. Not to mention it still used to be a Herculian task.
I loved taking out the snipers across the bridge with the AK 47. It used to be particularly difficult until I discovered a neat trick. The snipers across the bridge aim at the hall from a distance. A smoke bomb well thrown would impair their visibilty for some time. However, it can sometimes back fire. Anyways, once the smoke bomb covers the entrance of the bridge, the snipers lose sight and this is the best time for the terro snipers and gunners to take positions. Towards the end of my stay at IITB, I discovered that the over zealousness of CTs taking charge at the door (entrance to site A) could be handled better by an AK 47 gunner aiming at head height and firing continuosly rather than a Machine Gunner doing the same. I remember killing scores of CTs this way. They used to get into the line of fire :-))
This was perhaps the only map where the CTs dominated - I hate to lose and Aztec meant loads of frustration but still I used to play on this map just for the thrill.....