Being most of the links work anymore cause I moved the images I'll repost them.
Strength:
Colossus uses his strength to smash a barrier that the combined efforts of Dr. Strange, Wolverine, and Storm could not.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossusannual_4.jpg
Here Colossus catches a starship that was falling from the sky while he was injured. The ship was quite a bit bigger than the X-jet is and the X-jet weighs 85 tons. Add the momentum from it falling and it makes for a impressive feat.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/SecretWars009-09.jpg
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/SecretWars009-10.jpg
Colossus uses his strength to brace the ceiling of a underground base where a earthquake caused a massive avalanche. The base was over 100 meters underground and the added weight of the avalanche made the feat even harder.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossusavalancheMFF3.jpg
A similar feat here but Colossus was holding up a huge collapsing hospital while the X-men rescued the patients.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossusholdinahospital.jpg
Here Colossus carries the X-jet two miles to shore while it was sunk in the ocean. The X-jet weighs 85 tons and was completely filled with water.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossusliftingX-jet_2.jpg
Colossus smashed a army tank with a single punch.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossussmashinatank.jpg
Here Colossus overpowers the hydraulic press in the Danger Room while it was stuck at full power. A press that size would have to able to press thousands of tons. Oh yea it's true.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossussmashinthedangerroom.jpg
While shackled to a magma pit with Vibranium bonds Cyclops shoots the pit from under Colossus then Colossus rips the Vibranium bonds to set himself free. A side note Colossus was glowing red-hot also. Durability feat too.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossusandmagmapit.jpg
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossusandmagmapit2.jpg
Colossus easily and steadily holds a 35 ton piece of equipment while Nightcrawler hooks it up.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossus35tons.jpg
Stops the momentum of a decent sized boat and pulls it back to the docks with his strength so Douglock can board it.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossusholdingboat_Exc114.jpg
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossusholdingboat2_Exc114.jpg
Smashes his way through countless tons of impregnable rock with his fists as his brother Mikhail described the cave.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossussmashin.jpg
A similar feat here. While in a cave Colossus punches through the solid rock wall and leads the X-men to freedom.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossussmashin2.jpg
While doing a little farm work Colossus easily pulls a massive plow with one arm. It's harder than you think.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossusplowin.jpg
Grabs and tosses a military truck straight into the air while Havok blasts it. This was a armored truck too filled with weapons.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossuslifingtruck.jpg
Easily tosses a 50ft Sentinel.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossusjudotossinaSentinel.jpg
Has to carefully lift a tanker filled with propane and move it out of town while trying not to crack it in the process. To top it all of it was on fire also and in danger of exploding.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossusliftingtanker.jpg
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossusliftingtanker2.jpg
Rips open the jaws of a T-Rex and crushes it's skull with a single blow.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossustashinT-rex.jpg
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossustashinT-rex2.jpg
Tosses a huge metal arm and smashes it against the wall.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossus2unc136.jpg
Uses his strength to dislodge the Evolutionay Accelerator and tosses it smashing it in the process. A object that size might weigh 25 tons or so.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossustossinMFF4.jpg
Smashes his fists on the ground causing a wall to collapse on Sauron.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossussmashingMFF4.jpg
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossussmashingMFF4-2.jpg
Breaks out of his steel shackles then proceeds to kick the sh!t of of some Savage Land Mutates.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossusgiantMFF4.jpg
Wolverine wants to bet Colossus a case of Beer that Colossus cannot rip a tree out of the ground. Well Colossus does that and sends the tree flying up high into the sky to where Storm has to fetch it. Wolverine was impressed as his repsonse was "hmmph!".
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossusbettingCXM39.jpg
Holds up a decent sized Elephant with one arm.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossusliftinElephantunc378.jpg
While in micro form Colossus still had sufficient enough power to smash the door to the mansion.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossussmashingdoorXmicro2.jpg
Easily tears through the titanium hull of the X-jet.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossussmashingxjet.jpg
Retrains Iron Man who was unable to break Colossus' hold.(Iron Man was under the influence of a outside force but still had his abilities).
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/ColossusandIMIW2.jpg
Colossus rips the engine out of a speeding semi with a trailer.
http://i31.photobucket.com/albums/c379/Doggydogg/Colossus/Colossussmashinsemi.jpg