Any time you have a game that lasts more than one night (my husband and I have had some epically long Boggle competitions), Excel is exactly the right tool to keep track of results -- not only does the spreadsheet format easily keep numbers where they belong, but when the game finally ends, you can print off a line graph showing your progress toward victory mapped right over your partner's progress toward final defeat!
I'm a big fan of collectables, whether it's a geeky collectable card game or a more serious philatelic pursuit. Excel provides you with the ability to list not only quantities of various elements, but qualities as well -- and it makes the task of sorting by quality as easy as 'Sort By 'Mint/New/Used'.'
Excel spreadsheets make great schedulers. For example: scheduling your kids' chores, color-coding so that they have no excuse for not knowing what their duties are, and actually printing off the sheets and putting them on the fridge with a marker nearby for easy check-off. Excel makes it easy.
Organizing your Spice Rack
My husband and I have one of those rotating spice racks that has 10 bottles per side on four sides. When we realized that we didn't particularly care about 'pizza seasoning' because we always combined our own spices, we ditched half of the spices in the rack and then made an Excel spreadsheet listing all of the spices and spice mixes we used more often, hide the rows that contained the ones we used least, and alphabetized the remaining 40 and arranged them alphabetically on the rack. We keep the spreadsheet around in case there's any confusion about what is supposed to be where.
Obviously, Excel is an excellent tool for keeping track of the household budget. Tagging expenses with labels like 'food (home)', 'food (out)', 'entertainment', 'clothing', etc. makes it easy to not only Sort By those values, but to create charts that show you just how much of your monthly money is going places that could be cut out in a pinch.
Right up through graduating college, my husband I use used Excel to chart various science projects. With Excel's ability to reference other sheets in formulas, even very complex information can be summarized neatly on the front sheet of a multisheet array of data.
When you've got options like trying to decide where to purchase vitamins (in which each store sells different quantities of pills for different prices and in varying concentrations), you basically MUST have Excel in order to make the most well-informed purchasing decision. There's little other way to sort that much data.
When you're on a diet, whether you're tracking calories, carbs, or grams of fat, being able to put the data into a consistent, organized place is key. Excel offers you that place as well as tools to easily sum up your daily totals and chart your progress over time.
Making a Channel Guide
My husband and I upgraded to digital cable a while ago, and the number of channels we had do deal with was phenomenal. By putting them all into Excel, color-coding them by what rough genre each channel consisted of, and highlighting the ones we watched the most, we were able to put together our Favorites list without losing track of the more obscure channels along the way.
I once had a favorite conditioner, and then they went and changed the formula, and it stopped working for me. The solution? I tried a dozen different kinds of conditioner, put every ingredient from every bottle into Excel, and then eliminated the ingredients from every bottle that didn't work until I had a small list of ingredients that were shared between the few bottles that did. Then, I went and found the least expensive conditioner that shared those ingredients -- and now I have a new favorite conditioner.
Planning Camping Trips
When you've got a limited quantity of spaces and you need to make sure everything is going to go, Excel is a great tool. List everything you need, where you're going to be able to put it, and print off two copies - one alphabetized so that you can check it off and make sure you have it all before you leave the house, and one sorted by the 'where it is' column so you can find anything efficiently once you've hit the road.
Of course, there are dozens if not hundreds of other uses for Excel around the house; this is just barely scratching the surface. If you have hobbies like playing poker, Excel's hypergeometric distribution function can tell you the chance of getting a particular card in your next draw. If you like to garden, Excel can chart up the last few year's temperature data and give you an idea of when it's safe to plant what. The possibilities are endless.