Star Wars: Heir to the Empire trilogy, Spectre of the Past and Vision of the Future (Timothy Zahn), all of the X-Wing books save Isard's Revenge (Micheal A. Stackpole and Aaron Allston), I, Jedi (Stackpole again).
BattleTech: Anything. Everything. But to hell with MechWarrior: Dorkage...I mean, Dark Age.
Most Tom Clancy, but particularly Red Storm Rising, and Patriot Games.
The Starfist series, by David Sherman and Dan Craigg.
Anything by Dick Francis. Haven't read a book of his I haven't liked.
The Berserker series, by Fred Saberhagen, with the exception of Berserker Fury. (Which is a thinly disguised recounting of the Battle of Midway with a crap extra plotline thrown in.)