Monopoly Streets

This is easy if you have a friend to help you boost.
1. Join an Xbox Live party with your boosting partner.
2. Go to "Play on Xbox Live"
3. Choose "Create a Custom Match"
4. Choose any board or city
5. Choose a game type (I used Speed Die but it really doesn't matter)
6. Set Player 2 to RESERVED and all other players to CLOSED.
7. Press RB and invite party to game
8. After your partner joins the game both players hit A to start the game
9. Whoever is assisting just declares bankruptcy after their first turn and the other player gets a win
10. Repeat 10 times for each player

If you don't have a friend to boost with, this can take a while to get. Here's a strategy to unlock this achievement a bit quicker:

Create a ranked 2 person Speed Die game.

Once you get a color group (preferably orange, red, yellow, green or dark blue, although magenta will do), build a house or two on the first property (Magenta=St. Charles Place, Orange=St. James Place, Red=Kentucky Ave, Yellow=Atlantic Ave, Green=Pacific Ave). Leave some cash available if there are still unsold properties remaining.

After all the properties on the board have been purchased, mortgage all the properties you own that are not in your best color group (including any other color groups you may own, and any railroads and utilities).

When you have the cash, continue building houses/hotels on your color group, always having 1 extra on the first property. Leave some cash available in case you land on one of the other players properties (more if they have a color group with houses). Rent increases significantly once you have 3 houses on a property.

When the other player rolls a Mr. Monopoly on the speed die, they will be forced to move to the next property that you own, and is not mortgaged (the first property in your color group). If you have 3+ houses or a hotel, they will owe quite a bit in rent. After this happens a few times, the other player will be forced to declare bankruptcy.

This isn't a surefire way to win, but I won 12/14 games with this strategy.
***Keep in mind that your win may not count if the other player leaves the game before Mr. Monopoly declares you the winner.***

Just got the achievement.

Important points:
1- Must be a ranked match
2- The other players don't necesseraly need to finish the game. e.g.: if you're playing against another player and he leaves, the IA takes over. If you win, this still count as an online win. (got the achievement during one situation like that)

Cheers.

Difficulty: 1/5
Time Needed: 2/5
Not a hard achievement if you can find someone to help you. Once in the game with a helper after your helper rolls have them select the option declare bankruptcy and then you will be counted for the win. Do this ten times and the achievement will unlock.