What accessory could you not do without?

We have a caravan fridge, but it's always full of stuff like food.  We needed somewhere to keep drinks cold.  This last year I decided to buy one of these - a Mobicool B40 DC/AC fridge.  It has pride of place in the awnings - it houses any drinks we need to keep cool and doubles as an overflow for the main fridge .  The trouble with the caravan fridge is that after you have put food in, there never seems enough room for those the large bottles of coke/ white wine/beer or whatever.

We transport it in the car and it keeps stuff cool enough while travelling - works off the cigarette lighter.  We can have a cold drink while travelling.  In the awning it works of the mains electric - and it is more efficient than the caravan fridge (but don't tell the wife).

For main holidays, I wouldn't be without it now.  It is the best accessory/ piece of equipment we bought last year.

Which piece of equipment/accessory could you not do without?  It just might give others some useful ideas.