Verhoeven and Arnie have said that they believe it's all a dream of Quaid's.
If that's the case, why did Quaid have dreams of Mars and Melina prior to going to Recall?
Withholding response until pic of chick with three boobs is posted. 
Original Inception. Dream within a dream.
Yes it's a dream.
The melina he meets is the melina he asked for from his dream.
Start from the premise he has random dreams about some chick
His recall experience is just using that image in the recall memory.
Note the package he takes at Rekall is called Blue skies on Mars.
The scene with the doctor is legit and he genuinely chooses the option of permanent psychosis "the walls of reality will come crashing down"....
What happens after he kills the doc?
Cohagens forces smash through the walls
Oh, good point LS
SCREEEEWWWW YOOOOUUUU!!!!!!
I never thought it was a dream because they come out and state they hadn't injected him yet.
And that's a scene Arnie isn't even in. So why was he dreaming about what other people are doing/saying when he's not around?
That's bad storytelling if so...
YA but how did he get in that Johnny Cab?
I don't think it actually showed Melina's face in the opening dream sequence. 
Powdered Toast Man - Withholding response until pic of chick with three boobs is posted.
Voted Up disbeliever
SEE YOU AT THE PARTY RICHTER!
I love how Arnie and Ironside are shooting the shit out of each other in what are essentially golf carts with doors.
They are 10 feet away and can't hit each other. Yet Arnold makes lethal hip shots to scores of soldiers.
Total Dream
Wolfs Law - I don't think it actually showed Melina's face in the opening dream sequence.
I believe you're right
That was choice Sharon Stone. Good lord.
It's real..... When Hauser was undercover he fell in love with Melina..... He knew he would be found out that he was switching sides and planned the whole "Quaid" thing with Cohagen, he was kidding Cohagen that it was to kill the rebels but in reality it was to protect himself and Melina.
The whole plan turned out pretty much as Hauser wanted it to.....
The book of the film explains this but the film didn't do too good of a job explaining Hausers true feelings when he and Cohagen came up with the plan..,,,
I want an answer to Benny's question. Has he ever fucked a mutant?
There are so many scenes in the film that pretty much prove it isn't a dream....
1) the fact he's dreaming about Mars (OK, it could be a dream within a dream.... But No)
2) The conversations between Lori and Richter when Quaid wasn't present
3) the interactions between Richter and his partner when Quaid wasn't present
4) Cohagen smashing the fish tank
5) subtle glances Quaid couldn't see from the guy at the construction job and Bennie....
Lots more but that's all I can think of right now
TGP - There are so many scenes in the film that pretty much prove it isn't a dream....
1) the fact he's dreaming about Mars (OK, it could be a dream within a dream.... But No)
2) The conversations between Lori and Richter when Quaid wasn't present
3) the interactions between Richter and his partner when Quaid wasn't present
4) Cohagen smashing the fish tank
5) subtle glances Quaid couldn't see from the guy at the construction job and Bennie....
Lots more but that's all I can think of right now
Number 5. Dude was pissed that he was talking about Mars and going to Recall.
TGP - There are so many scenes in the film that pretty much prove it isn't a dream....I have third person dreams where I'm an 'observer' rather than an actor. Lots of people do
1) the fact he's dreaming about Mars (OK, it could be a dream within a dream.... But No)
2) The conversations between Lori and Richter when Quaid wasn't present
3) the interactions between Richter and his partner when Quaid wasn't present
4) Cohagen smashing the fish tank
5) subtle glances Quaid couldn't see from the guy at the construction job and Bennie....
Lots more but that's all I can think of right now