A Time of War is, in my opinion, one of those "genre-definitional" games that people should get if they are at all interested in a certain genre of game; science-fiction giant combat machine action being the genre of choice.
It's made by Catalyst Game Labs, which vouches for its quality even before you begin reading it. I'd say that it's got among the highest production values of tabletop games out there; the art is all impeccable, the typesetting works well, and it's got a lot of content for $15.
If you've ever played BattleTech, you know how much fun it can be to suit up in a giant 'Mech and blow away some enemies of your favorite choice, and A Time of War does a good job at letting you catch the "downtime" of 'MechWarriors and their compatriots, focusing on both fighting and more peaceful agendas outside the cockpit.
Content: 5/5 (Battletech has an incredibly rich universe, and A Time of War brings it through both in fluffy and crunchy ways)
Art/Typesetting: 5/5 (High quality, very pretty, and plentiful without feeling like padding)
Writing: 5/5 (No unusually obnoxious ambiguities or glaringly bad typos, plus it was technically excellent)
Awesome Factor: 5/5 (What's better than a setting where you can get back at the guy who just snubbed you by walking your 95-ton war machine through his house?)
Interest: 5/5 (The joy of my childhood still keeps on going strong)
Maturity: 14+ (Scantily clad women in the art and some more violent focuses earn it a slight cautionary rating)
Value: 5/5 ($15 isn't exactly the cheapest you can get a game, but A Time of War has a lot of stuff for that $15).
[5 of 5 Stars!]