I am basing this off of the most time spent with certian games.

In no order:

1. Jane's USAF
2. Ace Combat 04
3. Homeworld 2
4. Half Life 2
5. Pilot Wings 64
6. Counter Strike: Source
7. Red Orchestra: Ost Front
8. Unreal Tournament 2004

A bit less...

9. SWAT 4 with expansion
10. GRAW 1/2

Anybody care to tabulate all these takes and see what the SimHQ top 10 would be?

1. Microprose's F-117A
2. DID's Total Air War
3. DID's EF2000
4. Graphsim's F/A-18 PSF

EDIT:
++++++++++

5. Road & Track's Need for Speed SE (gold of original)
6. ID's Wolfenstein 3D
7. ID's DOOM
8. Microsoft's Age of Empires (original)
9. Lucas Art's Dark Forces
10. Microsoft's Gorilla, QBasic game which came with MS-DOS 6.22 I believe (the office favorite, right behind Links386).

Also spent a lot of time on Test Drive and Stunt Driver, but not so much to make the list.
++++++++++

I don't feel these are better flight sims than the big boys Falcon 4.0 and Jane's F/A-18, I've just spent (and still spending) much more time with them because they better satisfy the Tom Clancy/Craig Thomas reader in me. The only thing keeping me from playing more F-117 is that DOSBox gets kinda slow on me as a mission progresses. I still love the limited-war picture-taking recon missions, maybe plucking a missile boat on the way out of a photo shoot.

EF2000 and TAW are still the closest and most current games I've found to satisfy my style of game play, although I very much appreciate F4 and F/A-18 for what they are. I keep a PC around just for playing F/A-18 under Win ME, at least for practicing Carrier traps at night and/or during a lightning storm.

Graphsim's F/A-18 PSF (AKA Hornet Korea) is also one of my all-time favorites and how I came to find SimHQ, only now am I filling that void with Jane's. HK/PSF has nice training videos and an excellent full-screen high-rez mission recorder, although I love JF/A-18's dark and menacing EF2000-like feel (the GUI music really helps to set the mood).

I'm much anticipating what LP comes up with in a Hornet (not stealth but I love it anyway), but I have enough right now to keep me busy for years.

Couldn't agree more. Be very interesting to see a histogram of these selections

Ooops, I can't count!

My post above being edited...sorry.

In no particular order:

Wizardry - Apple (at a friend's house)
F-18 Interceptor - Amiga
Dungeon Master - Amiga
Zyll - PC
Jet - PC
Chuck Yeager's Air Combat - PC
Star Flight - PC
Duke Nukem 3D - PC (particularly death matches after work)
Jedi Knight: Jedi Academy - PC and XBox
Golden Eye - Nintendo 64

Honorable Mention-

City or Heroes

Elf

Fs2004
HalfLife
Black Hawk Down 
GTR 2002 mod (yes!)
Operation Flashpoint
Rainbow 6 early series
Need For Speed SE: Road and Track (first game of the series)
IL-2 Sturmovic
Ef2000
Jedi Outcast

Wow, good thread.

Let's see, in kinda chronological order:

1. FS98 (and through FSX)

2. EAW

3. Mig Alley

4. B-17 II

5. Falcon 4.0

6. Jane's F/A-18

7. IL-2

8. LOMAC

9. The Sims series

10. Silent Hunter 3

10.5 Spore (graphics are so cute!)

Most of these I have never mastered, if I hadn't foolishly junked/given away my older computers, I'd still be playing them, I think.

Jane's F/A-18
Falcon 3.0 (Gold)
Secret Weapons of the Luftwaffe
Sim City 4
LOMAC
Jane's Sub Command
The Elder Scrolls III: Morrowind
Baldur's Gate
Diablo
Sea Dogs

It's tough to narrow it down to just 10, but I tried to limit it to games that I have continued to load and play on each new system over the years--that is until hardware or system technology has made it difficult if not impossible to do so. I actually just started a run through of NOLF again just last week and it runs great on Vista 64 bit and current NVidia GPU drivers

In no particular order

NOLF
EAW
Panzer Commander
Shogun TotalWar
Medieval Total War
medieval II TotalWar
SeaDogs
Fallout 3
Stronghold
Halflife 2

Maybe we should start a thread listing our next favorite 10 games. I know I have a full list.