Still has to be the original Axis & Allies from the late 80's early 90's

Others thoughts?

ones that i always used to enjoy lots include

Kingmaker (until the endgame which usually stalemated)
Divine Right (not sure why i liked this but i did!)
Squad Leader (the original not the 372 volumes of ASL)
Machiavelli (a renaissance variant of diplomacy with lots of skullduggery rules added in)
Civilisation
Junta
Judge Dredd - always good for a laugh

Yeah, I'd plump for Kingmaker too. Even if you got knocked out you could still join up again.

Hardly ever played wargames board games. However, we did play a lot of a game based around Frederick the Great at Uni, but the name escapes me.

Some titles not yet mentioned:

Titan
Gunslinger
Kings & Things
Age of Renaissance

Old favourites are King Maker and Talisman, although we've recently been playing quite a lot of Arham Horror which is a scream 

Shogi. Single greatest combat game ever.

Waddington's Battle of the Little Big Horn. Virtually impossible for Custer to win but great fun all the same.
DP

Original Squad Leader

OGRE/GEV

Up Front (actually more of a card based game)

Kingmaker
Judge Dread Block mania

Original Squad Leader
Bang!
Munchkin

Chess 

AH Starship Trooper (pre movie version)
Cry Havoc
Snit's Revenge
Ogre
Awful Green Thing from Outer Space

Kevin Zuckers napoleonic campaign boardgames. Published over the years by Operational Studies, Avlon Hill, Vicotry Games
1796-97
1805
1806
1807
1809
1812 Russia
1813
1814
1815
He has basically covered all the major campaigns, great games that really show you the campaigns. Not only great games but fantastic tools to understand the campaigns, now he only needs to do Spain.
http://www.napoleongames.com/
William

Awful green things has to be right up there, I've got 3 sets  . Even done ship to ship battles.

Brittania as I love the whole 'what if' feeling and I could get non wargamers to play.

Junta. You have to just laugh.

Still have fond memories of Risk and Civilisation.

War on terror. The daily mail raged against it, so I got a copy. Great fun!

I forgot (beacuase I really don't consider it a war/board game) CARCASSONNE fantastic game after a few light-fallling-down-waters!