“
We have more days to live through than pleasures. Be slow in enjoyment,
quick at work, for men see work ended with pleasure, pleasure ended with
regret.
”
—
Baltasar Gracian
Depending on one view's the time travel spokes in the time line the show, the 815 survivors were only on the island for a short time period.
In reality, the real mean time was only around 116 days: 101 days through December of 2004, and about 15 days on the re-emergence in 2007 (or that is what we assume the date was based upon Rose and Bernard's alone time in their camp.)
If we look at the time the characters had on the island as their last time on Earth (so to speak), who had the most pleasure in their island time?
Locke certainly loved his new outback persona. He thought of himself as a leader who could control the situation. People listened to him for once. But those pleasurable moments were fleeting for Locke.
Sawyer had his own personal moments of joy. He was at home being the lonely island troublemaker. People had to come to him to make deals for necessary supplies. He had no desire to belong to the group, especially when he got fringe benefits from Kate. If not for the Jacob-MIB dogma, Sawyer may have been content to be a Robinson Caruso island resident for the rest of life.
Hurley was comfortable on the island. It is interesting to note that he never really spoke about his mother or father on the island. He kept his wealth a secret until he made what he thought were trustworthy friends (and then they did not believe him). Hurley's new friendships made his island stay more than bearable. He was surprised that people accepted him for himself. His island time was really a vacation from the stresses and anxiety of his real life.
On the flip side, no one can say that Jack had a very good time on the island. He was under constant stress to be the leader. People wanted him to make decisions for them. He had to treat their wounds, maintain their safety, and hear their complaints. Over time, it beat Jack's psyche down to being comfortable in the role of Dharma janitor.
Sayid was quietly comfortable at first in the beach camp, but he felt the prejudice and distrust from the survivors early on. He was brought up in an emotional and confrontational culture. He knew he did not fit in, but he stayed on the edge of the group because he was useful, resourceful and a means of protection. Sayid enjoyed that role of protector, until his inner evil turned him back into a mindless torturer. At that time, Sayid became depressed and useless waiting for a means to end it all.
Rose and Bernard probably made the most of their extended time together. Rose had no use for most of the survivors. She hated the politics and whining in camp. Bernard was just grateful for the extra time he had with his wife. Once they left to have their own camp, they were a happy couple again.
But all these impressions and actions of these characters happened in a short time frame. One either quickly accepted your role on the island or you were miserable and your fate was sealed by the island. It could be viewed as the countdown to execution that condemned prisoners would have prior to the gallows. The visitors to the end may or may not realize that their days are numbered, and that their lives were about to be extinguished so the island is the last playground they will ever know. Some left the island with regrets. Some left the island with pleasurable memories and friendships. Some never left the island.