It would help if you would share where your "Dream" trip desires would take you. I am sure we could help you with that trip on this site.
For me, it would be Paris, Marriott C-E, for one week. For 360,000 points you would get a break on air fair, and I would forget the rental car. What a week you could have!
For more information and options, go to the "Rewards" section on the site, and view the packages and options. One thing to consider is that you may want to book your trip very early, as the great places tend to book up early.
Nice total to be spending! Without knowing where you are based or how many travelling, it is difficult to make a suggestion.
Personally, I would take one of the Travel Packages ... the 330K one that gives 120K air miles and 1 week in a Cat 7 hotel. That would give me 2 British Airways return flights from London Heathrow to Washington DC (Dulles) in Premium Economy and a week in the JW on Penn. If you were to do this in reverse, the best Marriott (personal preference) in London would be County Hall, but that's a Cat 8, so would need a 360K package.
If you share your 'dream' as I have just seen Jerry suggests, we may be able to be even more creative.
Let's go stay at a couple of Cat. 7 Hotels this year.
The first stay can be at The Cayman Islands. Just you and your sweetie. 5 nights will set you back 140,000 points. Add a 6th night for 35,000, if you'd like.
The second stay can be more family related. Lets take the two little ones to Vail Marriott Mountain Resort and Spa if you're into fun in the snow. Same tab..140 for 5 nights or 175 for 6.
Total 280,00 up to 350,000....lets you keep 50,000 to 120,000 in the bank.
Cat. 6 Hotels work, too. If it's sun and fun the family likes , let's head to one of the 7 Marriotts or 1 JW in Orlando. The 5 nights at 120,000 or 6 at 150,000 may save you enough to plan another trip next year!!!
Nothing clever, but there are a lot of dream vacations out there.