Mine was 8043 after 18 dark years without LEGO Technic.
At that time I successfully build a RC-submarine (non lego) and searched for the next model for an excavator, which is in a metal Version with real hydraulics quite expensive and you can not easily rebuilt it, so the 8043 brought me back.
The biggest Advantage is that I now can build and play since 5 years together with my chidren and not anymore alone in my Workshop in the cellar.
For example my youngest daughter is no nearly 2 and she really loves the middle scale AWD SUV MOC from Madoca and If somthing falls off, we play repair shop LEGO is so much fun...