As an Artilleryman, I am torn between the M110A2 and M109 series - particularly the A6 version. I agree that the M88, particularly the A2 or HERCULES version, is great recovery vehicle.
On the wheeled vehicle front, I would have to say the HMMWV series. The M151A2s were nice in their day, but outclassed by the current HMMWV series (of course, you can't sneek around with a HMMWV the way you could with any of the Jeeps!).
I'd rather be a Soldier with a mule and mountain gun, than Knight of old, with spurs of gold, or Roman, Greek or Hun. For when there's trouble brewing, they always send for me!
Mortui Non Mordent - Celeritas Et Accuratio