Who's the real bad guy: Charles Widmore or Benjamin Linus?

In 5x07, "The Life and Death of Jeremy Bentham," the writers further develop the characters of Widmore and Ben. Up until now we've primarily considered Widmore to be the bad guy. He sent a team of mercenaries to the island to capture Ben and kill all other inhabitants. Ben, although he may be dishonest and his agenda has never been entirely clear, it appears as though he has always had the best interest of the island in mind. Before Locke, he was the only person on the island who was able to speak with Jacob, at least in the present time. The only time that he actively acted against the island's wishes was when he tried to kill Locke after it became clear that he would become the new leader of "the Others" but even that was more out of jealousy than an act intended to harm the island.
In this episode, however, we see a new side of Widmore. He explains to Locke that the only reason he granted the mercenaries the right to use lethal force was because he was willing to do whatever it took to remove Ben from the island. In trying to win over Locke's trust, he reveals that he was the former leader of "the Others" and Ben tricked him into turning the donkey wheel to move the island. That might explain what Widmore meant when in 4x09, "The Shape of Things to Come," he said to Ben, "I know everything you have you took from me," and "That island's mine, Benjamin. It always was; it will be again." Once Widmore persuades Locke to side with him he even dispatches Abaddon to help Locke find everyone who left the island. While the part about Ben taking the island away from Widmore seems very likely, it's possible that the only reason Widmore helps Locke is because he wants to find the island for himself. Caesar and Ilana could then be agents that Widmore hired to secretly act on his behalf. Even so, it's still unclear as to whether he's good or not.
As for Ben, it is quite clear that he too has a devious scheme up his sleeve. Sayid went from working for Ben to distrusting him entirely for reasons that are still unclear. Before Locke left the island, Christian Shepherd more or less insinuated that Locke should not trust Ben. And after getting Locke to indicate Ms. Hawking was the keeper of information who would be responsible for getting everyone back to the island, Ben strangled him to death. Like with Widmore, though, it is unclear as to what his true motives are.
If you have an opinion on the matter I'd be interested to hear who you think is the bad guy. Or if you have any other ideas such as neither is bad, they both just want to return to the island and lead "the Others" again, then share those thoughts.