Piccolo (after merging with Kami): 40,000,000
Imperfect Cell: 40,000,000
Imperfect Cell (after absorbing humans): 45,000,000
Well we finally see Cell and what an ugly dude! without the humans he would probably have been an equal match for the now super strong Piccolo who has merged with Kami and at this point Piccolo is the strongest being on Earth (yip - even stronger than a super saiyan)
Piccolo vs. Android 17
Piccolo: 40,000,000
Android 17: 35,000,000
This battle really should be in the Android saga but I put it here as technically the Android saga has ended. Piccolo would of defeated 17 but thanks to Cell showing up it is a draw
Piccolo and Android 17 vs. Imperfect Cell
Piccolo: 40,000,000
Android 17: 35,000,000
Imperfect Cell: 45,000,000
Piccolo and Android 17 take on Imperfect Cell and as a result Piccolo is nearly killed and #17 is almost absorbed until Android 16 intervenes
Android 16 vs. Imperfect Cell
Android 16: 40,000,000
Imperfect Cell: 45,000,0000
Semi-Perfect Cell (after absorbing Android 17): 65,000,000
Android 16 does quite well againts Cell but after Cell absorbs Android 17 he has no chance
Tien vs. Semi-Perfect Cell
Tien: 4,500,000
Tien's Tri-Beam: 13,000,000
Semi-Perfect Cell: 65,000,000
Although Tien's power level is no match for Cell, Tiens "tri beam" distracts Cell long enough so Androids 16 and 18 can escape. I don't see why they renamed Tien's attack as they real name (Kikoho) was much better. I figure the Tri Beam multiplies the users level by three for that attack but doing this almost definitely causes great strain. It is able to hold off Cell because of the type of the attack
Super Saiyan Vegeta vs. Cell
Vegeta: 80,000,000
Semi-Perfect Cell: 65,000,000
Perfect Cell: 125,000,000
Vegeta after training in the Hyperbolic Time Chamber is too much for Cell and probably would of killed him if not for his toying instead Cell becomes perfect and knocks Vegeta unconscious
Super Saiyan Trunks vs. Cell
Super Saiyan Trunks: 75,000,000
Ultra Super Saiyan Trunks: 130,000,000
Perfect Cell: 125,000,000
I bet your thinking Hey! Wait a minute if Trunks had a power level higher than Cell why didn't he win? Well thats because when you go Ultra Super Saiyan your muscles grow so large it slows you down this is why Trunks could not win
Goku and Gohan Exit the Hyperbolic Time Chamber
Super Saiyan Goku: 110,000,000
Super Saiyan Gohan: 120,000,000
Not much to say here so I'll just leave it be
Karoni, Piroshiki and Hercule vs. Cell
Karoni: 70
Piroshiki: 100
Hercule: 120
Perfect Cell: 125,000,000
In this pre match Cell deflects Hercule's two best students by simply using his energy to send them from the ring and Hercule is slapped into some nearby mountains. Hercule is actually quite strong which is why he survives
Goku vs Cell
Super Saiyan Goku: 120,000,000
Perfect Cell: 125,000,000
Perfect Cell is only marginally stronger than Goku but strong enough to over power Goku
Gohan vs. Cell
Super Saiyan Gohan: 130,000,000
Super Saiyan 2 Gohan: 325,000,000
Perfect Cell: 125,000,000
Z Warriors vs. Cell Juniors
Yamcha: 3,500,000
Tien: 5,000,000
Krillin: 5,500,000
Piccolo: 55,000,000
Super Saiyan Vegeta: 100,000,000
Super Saiyan Trunks: 105,000,000
Super Saiyan Goku: less than 120,000,000
Super Saiyan 2 Gohan: 325,000,000
Cell Juniors: 120,000,000 (each)
Yamcha, Tien and Krillin have no chance against the Cell Juniors and neither do the rest of the Z warriors. Goku is still worn out from his fight with Cell which is why he is beaten. The Cell Juniors are probably a bit weaker than Cell himself. Super Saiyan 2 Gohan is far too powerful for any of the Cell Juniors
Gohan vs. Cell
Super Saiyan Gohan: 130,000,000
Super Saiyan 2 Gohan: 325,000,000
Super Saiyan 2 Gohan (injured arm): 305,000,000
Perfect Cell: 125,000,000
Semi-Perfect Cell (after spitting out #18): 65,000,000
Ultra Perfect Cell (after self destructing then coming back): 300,000,000
The battle that I had been waiting for! Gohan has the ultimate power and then what does he do? He pulls a Goku and wastes time! However even with his injured arm he still manages to vape Cell and become the galaxys greatest fighter!