I've owned both. Both great choices.
Monster Bash is gorgeous. They did a great job on the remake. If you have a large collection and play occasionally, maybe it has some lasting power. I feel like a mediocre player can see everything it does within a week of heavy play. I had a ton of fun with it, but it didn't last long. Same problem I had with MMR.
Dialed In is amazing. It gets crap for being a stupid theme, but I disagree. Nearly every WPC/ System 11 game had a stupid theme by today's standards. DI is a beefed up WPC style game. I played Mousin' Around for at least an hour today. What would happen if they released that title today? I think I've had DI for a couple years now. I've reached Armageddon a few times, still haven't gotten all of the Dialed In letters. It does seem doable. I don't play as much as I used to. It has some lasting power.
Both are great games. I'd be happy if I could play MB for a few hours a year. DI is a keeper. If I could own 30 games they would both be here.