I am going to name two units and you're going to pick the one you would buy based not just on strength but their movement, vision, price, etc.

Infantry - Mech
Recon - Anti-Air
Artillery - Rockets
Tank - Mid Tank
Neo Tank - Mega Tank
Lander - Black Boat
Stealth - Bomber
Fighter - Missiles
APC - Black Boat
APC - T-Copter - Lander (chose one)
Sub - Battle Ship - Cruiser (chose one)


My choices:

Infantry - I love to spam them! Plus they are faster than mechs
Anti-Air - Not as fast but hey, they are good against infantry, air units, and tanks.
Artillery - Cheaper and faster.
Mid Tanks - Slower but stronger!
Neo Tanks - Faster and Cheaper.
Lander - Able to load tanks.
Bomber - I tend to lose my stealths to easily.
Fighter - Able to go anywhere while the missiles take time.
APC - Resupplies units and transport infantry across land.
APC - I've never found much use for land, air, or sea transports unless its the only way to win.
Sub - I find them useful and it will stop Battle Ships. As for the Cruisers, just add a little spam to my sub (lol) and I'll win.


Anyway, just choose the unit you would pick and explain why.

Inf: Cheap and Effective
Both: Can't Deside Both Are Too Good
Artillery: Cheaper/Faster
Tank: Cheapter/Faster
Neo Tank: Fast/Boom
Bomber: Boom Boom Boom. (Don't ask)
Black Boat: Sea Raids/Healing
T-copter: Sami/Eagle FTW's/Greatest Distance
BattleShip: Best Range/Great Defence/Land Unit Owner

Mech: Can travel over mountains faster and are strong against tanks
Recon: Good against infantry and have terrific vision
Artillery: Cheaper and faster
Mid Tank: Much Stronger and not much slower
Neo Tank: Faster, can carry more ammo, cheaper, still very strong
Blackboat: Can repair units
Bomber: Can take out Mid Tanks and Neo Tanks in one shot (depends on CO)
Fighter: Faster and direct combat
Blackboat: Can repair and holds 2 infantry/mech
Lander: Transport ground units
Sub: Take out enemy battleships and landers, can dive

*BUMP*

Infantry - Mech
Recon - Anti-Air
Artillery - Rockets
Tank - Mid Tank
Neo Tank - Mega Tank
Lander - Black Boat
Stealth - Bomber
Fighter - Missiles
APC - Black Boat
APC - T-Copter - Lander (chose one)
Sub - Battle Ship - Cruiser (chose one)

Infantry: Best for spamming together with Artillery, higher movement, and lower deployment cost. Close call, since mechs are truly cost efficient and work wonders with Sami and Sensei.

Anti-Air: Wreaks havoc on infantry and provides a solid defense against aerial threats. Destroys any unit cheaper than its own kind, excluding Tanks and units it cannot hit. Great movement and decent vision as well.

Artillery: 'Nuff said.

Tank: Tends to fit my playing style, since I like saving money for higher end indirects. Tanks have better movement and more fuel, while still clogging chokepoints well. Two of these and two infantry can be purchased at standard price for one MD Tank. Quantity over quailty, I suppose.

Neo Tank: Reasons already stated. The Megatank blows in every reviewable aspect except for sheer power.

Lander: Landers can load ground units, while Black Boats cannot. It really depends on the circumstances, but I'd rather have these than Black Boats if I given the choice of one or another in battle.

Bomber: Stronger, cheaper, and doesn't burn as much fuel. Omni Missiles and cloaking capabilities do not outweigh the listed advantages, and an extra 2000g.

Fighter: More mobile, and worth the higher price tag. If we're in FOW though, I might opt for having missiles instead.

APC: More pratical in battles, since nearly all battles have ground units. These units are simply invaluable despite not having offensive capabilities. Cheaper by a 1:1.5 ratio.

T-Copter: Cheap as an APC, but can move without being hindered by terrain. Can be loaded onto Cruisers for safety, too.

Crusier, by DS Standards. Otherwise, a Battleship, since it can engage both naval and land units.

Infantry: Cheaper, Easier to get aroumd
Anti-Air: So what the recon can see farther? I slaughter!
Rockets: more damage and distance
Tank: Affordable, deals damage quickly.
Neo Tank: Not as strong, but nearly twice the movement.
Black Boat: Loss of carrying non-infantry, but now it can heal other sea unit fuel and ammo supplies.
Bomber: RAIN DESTRUCTION UPON THYNE ENEMIES!
Fighter: Moves faster, harder for enemy to stay out of range.
Black Boat: Carries twice as many infantry, can move up to the edge and resupply land units.
APC: Resupply ability ftw
Depends on the game:
AW1/2/DS: Cruiser, it's better against other sea units then the battleship.
AWDoR: Battleship, because it can both move and attack.