Diner Dash

There aren't enough players online to gain this legitimately so chances are you will need to boost this, you will need 8 people or 4 people each with two controllers (having more people does not make this take longer, you gain a win on the winning team regardless of who on the team scored more points). Create a private match set to Team Dash, Tip Wars, $5000 and invite your friends in (remember, all eight slots must be filled with somebody or an extra controller). Your best bet to make this go quicker is to use the restaurant Vishnu's Garden Café, and use the combo method listed for "I really ate the whole thing". You must play out the entire game. Have whoever is working on their win score $5000 as fast as they can. Rinse and repeat 19 more times.

Find boosting partners here: LINK