Windstar Cruises. My brother was asking about cruises. I told him we'd not been on many, but had research it quite a bit (before the age of blogs). We really recommend the Windstar cruises.
The Tahiti trip is amazing. The ship is just 400 feet long, all the cabins are the same and it is small enough to get into the very shallow lagoons. I'll never forget stopping the middle of the ocean to catch the sunset off of Bora Bora while looking at the four masts.
Also, it is casual, so you don't have to wear formal attire.
We also did the Istanbul to Athens leg and that was also great. Little less advantage in having a small boat, but it did mean we could get into Bodrum and see ephesus, while the bigger ships couldn't get in there.