The mountain over looking NE has to be guarded from Tank, Max, turret, sniper campers. The transition to other bases, Xenotech, Snake Ravine, or Broken Arch roads is very fluid. But Crossroads is the best of them all, (narrowly better than Indar Excavation because it is smack dab in the middle of Indar and a very busy position). There are so many great towers, especially in Indar! Indar Excavation, Regent Rock Garrison and Crimson Tower Bluff (in that order).
The flow of battles are so good, only stopping at powerful defensive chokepoint bases like Towers, Eisa, or the Octagon. During Esamir Alerts, this area is always hot.
The Eastern flank/lane of the Biolab is awesome as well, since it leads to interesting areas What's great is, the long lane is capped by a tower from the south and the north. There's always a back and forth, going up and down.
The North to South lanes so fun to fight in. These series of bases are always on fire during Tech plant alerts The network of roads and entryways between the Tech Plant and the satellites are brilliant. Each of the satellites are interesting and open to attack in many ways.