Since these topics are popular, I decided to make a few of my own.

Autobots

10: Ironhide
Machine/Earth
2400/1300/6*
A newbie to the Transformers World, he is loyal to Optimus.

9: Smokescreen
Machine/Earth
2300/1500/5*
During your Draw Phase, you may search your deck for a Machine-type monster instead of drawing regularly. Then deck is then shuffled.

8: Hot Shot
Machine/Fire
2600/2000/7*
Second-in-Command of the Autobots. He's very powerful in Optimus's time of need.

7: Jetfire
Machine-Union/Wind
2400/1000/5*
You may equip this card to either "Optimus Prime" or "Ironhide". Increase the equipped monster's ATK by 500 points. In addition, the equipped monster can attack twice during the same Battle Phase, but only if a monster was destroyed from the first attack. (Only 1 Union monster can be equipped to a monster at a time. If the equipped monster would be destroyed by battle, destroy this card instead.)

6: Red Alert
Machine/Earth
2000/1200/5*
During your Standby Phase, increase your Life Points by 700 points.

5: Blur
Machine/Wind
2750/2400/7*
You may pay 1200 Life Points during your Battle Phase. If you do, this card can attack your opponent's Life Points directly.

4: Sideswipe
Machine/Earth
1800/1200/4*
A newbie Transformer of the Autobot race.

3: Inferno
Machine/Fire
2400/2000/5*
This card may be Special Summoned from your hand if your opponent has 3 or more monsters on their side of the field.

2: Optimus Prime
Machine/Earth
3000/2400/8*
The leader and commander of the Autobots. He is very powerful and can Power Link with many other Autobots.

1: Optimus Prime, Super Mode
Machine/Earth
4500/4000/12*
This card can only be Special Summoned by sacrificing "Optimus Prime" after it has destroyed 5 monsters.


Decepticons

10: Tidal Wave
Machine/Aqua
2900-Union/2000/8*
This card can be equipped to "Megatron". Increase the equipped monster's ATK by 700 points. {insert Fairy Meteor Crush effect here} (Only 1 Union monster yadda yadda yadda)

9: Unicron (ok, he's not a Decepticon, but he's like one)
Machine-Ritual/Dark
3500/3000/10*
This card can only be Special Summoned by the Ritual Spell Card "Unicron's Awakening". You must also offer a number of monsters from your hand and your side of the field whose total Level Stars equal 10 or more. During your Standby Phase, Special Summon 1 "Minicon Token" (Earth/Machine/1*/300/200) in every empty Monster Zone on your side of the field in Defense Position.

8: Cyclonus
Machine/Wind
2300/2000/6*
A maniacal Decepticon that flys like a helicopter. He can get out of hand when attacking sometimes.

7: Demolisher
Machine/Earth
2250/1400/5*
This card can attack twice during the same Battle Phase.

6: Sideways
Machine/Dark
2500/1500/6*
A Decepticon the tricked and betrayed the Autobots.

5: Scorponok
Machine/Dark
2800/2000/7*
A Decepticon that has the power to revive Megatron, who met a creul fate in the battle with Unicron.

4: Starscream
Machine/Wind
2700/2300/7*
If your opponent only has monsters in Defense Position, this card can attack your opponent's Life Points directly.

3: Alpha-Q
Machine/Dark
3000/2400/9*
A Decepticon with the secret to reviving Megatron.

2: Megatron
Machine/Dark
3200/2500/10*
The leader and commander of the Decepticons. His cannon can be very powerful.

1: Cybertron
Spell/Field
Increase the ATK of all Transformers based monsters by 500 points.