The House series finale begins with House waking up in a burning building next to a dead heroin addict/patient. The majority of the episode is a series of flashbacks and hallucinations with dead or departed cast members where he debates whether or not he should just die in the fire. As he decides to live and rushes to the front door, he sees Wilson and Foreman are there. A beam collapses and they pull out a body that they declare is House’s. House is revealed to be alive, having switched his dental records with the addict’s. When did he switch them? He couldn’t have switched them after the fire, because that would involve going to a hospital that was filled with people who knew him. So he switched them before he ended up in the burning building, which means he had planned the whole thing.
Consider: House recollects all the events leading up to his being trapped in a burning building with a corpse, except the period of time between him diagnosing the patient (with a curable disease) and his waking in the building, which is notably absent. Furthermore, when he sees Foreman and Wilson outside the front door, he stops. We’re supposed to believe this is a sentimental thing, but if he was planning on faking his death, he couldn’t have witnesses seeing him leaving the building. Not to mention that the cause of the fire was never examined.
Also consider: There were no apparent signs that he had just shot up. Hallucinations are common in House's life. If nothing else, the fact that he was still in pain and able to think clearly, meant that he wasn't high. So if he wasn't doing heroin, why was he there? Also, the suicide debate he has with his subconscious. If we accept that he had planned to fake his death the whole time, we have to conclude that he wasn’t originally planning to kill himself. What could cause him to black out, and consider suicide? Murder. House murdered his patient.