The first three books of the Honor Harrington series by David Weber have some good action scenes in them: On Basilisk Station
, The Honor of the Queen
, and A Short Victorious War
If you liked The Forever War
, you might want to compare and contrat with Heinlein's Star Ship Troopers
if you've not alread read it. and for the love of god, avoid/ignore the movie. Also by Heinlein, The Moon Is a Harsh Mistress
has pretty engaging action sequences.