How are Lennie and George different from other people on the ranch?

In chapter one, George makes it clear in which ways they are different from other men. He and Lennie have just had a verbal altercation but have made up. George starts talking about their association with each other:

"Guys like us, that work on ranches, are the loneliest guys in the world. They got no fambly. They don't belong no place. They come to a ranch an' work up a stake and then they go into town and blow their stake, and the first thing you know they're poundin' their tail on some other ranch. They ain't got nothing to look ahead to."

He continues to say:

"With us it ain't like that. We got a future. We got somebody to talk to that gives a damn about us. We don't have to sit in no bar room blowin' in our jack jus' because we got no place else to go. If them other guys gets in jail they can rot for all anybody gives a damn. But not us." 

George believes that ranch workers are generally very lonely men with no family or any other ties. They do not belong anywhere and are wanderers who never settle down. He states that these men waste all their earnings since they have nowhere to go. If they should be incarcerated, no one would care. He and Lennie are different, though, since they do have something to look forward to, and they have someone (each other) to confide in and discuss things with. They "give a damn" about each other, which means that they care about one another.
Lennie takes great pleasure in George's exposition and urges him to continue. He believes that each one of them can rely on the other to look after him, unlike the others, who do not have that privilege. Furthermore, George and Lennie are going to get some money together and buy a few acres of land and, as Lennie states, "live offa the fatta the lan'." They are going to have a place of their own. They will have a home on which they can generate an income and be independent. The other ranch workers will never have something like that; they don't have a plan or anyone to share their dreams with.
It becomes clear that George and Lennie's relationship is truly special. Against the backdrop of loneliness and isolation, they are unique. Not only do the two men have each other, but they are also not as desperate as the others—like, for example, Candy, who has no one to go to should he be kicked off the farm. He is somewhat disabled and realizes that his time on the ranch is almost up. When he realizes that George and Lennie can offer him hope, he becomes part of their shared ideal.
Even a character such as Curley is not happy. Although he is the ranch owner's son and has a pretty wife, he is clearly not at ease with himself, unlike George and Lennie, who are comfortable in the knowledge that one will stand up for the other.
It also appears as if Lennie has become somewhat of a sounding board for George. He can expect his companion not to judge him. This is unlike the other men who, as Curley's wife most pertinently states, are  

"...all scared of each other, that's what. Ever' one of you's scared the rest is goin' to get something on you."

This fear is what drives the other men further away from each other and isolates them. George and Lennie, though, are not afraid to share their sentiments. Even though they at times have verbal altercations, these are soon forgotten. The two men feed off each other. The other men are too afraid to trust anyone—they fear their confidences could be used against them.
In the complete scheme of things, it seems as if Lennie and George are much happier than any of the other men on the ranch and are, therefore, much more privileged. It is a pity that their relationship ultimately comes to a tragic and unfortunate end.