As described in part 1 here: American Airlines and US Airways are formally merging their operations on March 30 of 2014. Although it's not a guarantee, history has shown that mergers between airlines tend to wipe out some of the best values and "sweet spots" in each program's redemptions. Here are some more tips on what to book at the current redemption rates.
1. Australia/Africa: Both Australia and Africa have historically been underrepresented because they're normally quite hard to get there. Australian flights in particular are extremely hard to find directly from North America and sometimes require round-about routings through Asia. Flights to Africa usually require layovers in Europe as well, which really increase the time involved in getting to the "dark continent". Still, if you can find availability, US Airways has some of the cheapest awards to both of these destinations. Australia and Africa are both 110,000 miles in business and chances are this will go up to the AA award prices of 125,000 miles and 150,000 miles in business.
2. Buy Miles: Some travel bloggers are vehemently against buying miles and some actively encourage it when the price is right. Personally, I espouse a middle path and have bought miles from time to time during US Airways' perennial 100% bonus miles promotions. Currently, they're having this promo and if you're looking to book some of these great sweet spot awards and need a small top-up, I'd highly advise that you do this. Also, if you think that you're going to be redeeming some awards with American miles in the future, this presents an opportunity to buy AA miles at around 1.8 cents, which is significantly less than the 2.5-3.0 cents per mile they normally sell their miles at. Of course your mileage may vary (YMMV).
3. Bonus: Crazy Routings: This is more of a general tip than a specific award routing that you should book, but this will probably be the last time where you will be able to pull a fast one on US Airways' booking system. For some reason, US Airways' tickets are manually sold and many enterprising travel hackers have gotten some outsized value out of this. For instance, I believe it was Scott at milevalue.com that booked a flight from North America with a stopover in Buenos Aires Argentina, and then to Barcelona Spain all for 100,000 miles in business. Maybe he was able to get away with this because the agent didn't have a very good grasp of geography and both cities are vaguely Spanish? Who knows? What I do know is that this was a great way to get flights to two continents for the price of one. There are other tricks out there, so give it a shot while you still can!
US Airways definitely had its quirks (no one way awards, strange booking process) but the award chart had many sweet spots which gave outsized values to many destinations around the world. Book one last award and take advantage of these deals before the merger.