This is, of course, a matter of opinion. My own view is that President Nixon absolutely needed to resign. I also think that it was best for the country that President Ford pardoned him. I think that this minimized the damage to the country from the Watergate scandal.
It was necessary for Nixon to resign from office. If he had not resigned, he surely would have been impeached and convicted. This would have meant that he would have been removed from office. In other words, the end result would have been the same for Nixon; he would no longer have been president. By resigning, Nixon made things easier and better for the country. He spared us months of partisan fighting over his impeachment. He also allowed us to get a new start with a different president rather than saddling us with a president who was completely hamstrung by the impeachment proceedings. Thus, his resignation was the best thing for everyone.
I feel the same about Ford’s pardon of Nixon. Watergate was already going to hurt us by reducing our faith in government. That was inevitable. However, if we had had to go through a trial of Nixon, it would have made things worse. The trial would likely have turned into a partisan conflict in which Republicans and Democrats could not agree on what result would serve justice best. This would have hurt our country even more. Therefore, I do not think that there would have been much benefit to having a trial that would have turned into a partisan circus.