Grams and Kilograms or Ounces and Pounds

We don't mess with pounds and ounces in Brazil...we're metric people.

Like most responders, I am adept with both. I grew up with lb/oz. However, especially for bread I use metric measures because it is so easy to use the baker 's percentages.
When guessing during measuring, I guess the lb/oz better. Fewer increments required.
I rarely use cup or other volume measures unless I am following a recipe precisely.
We do need to have a feel for imprecision, especially if a recipe has been mindlessly converted from one of units to another.

I spent some time in England last November and bought several cookbooks while I was there. Many of the recipes use teaspoons and tablespoons, then switch to grams for larger measurements. When I got home I bought a new digital scale to use when cooking from these cookbooks. Now I use the scale all the time. If a recipe uses metric measurements, I use kilos and grams, if it uses US measurements, I use pounds and ounces. I'm not much of a baker, but I'm trying to learn, so I weigh everything metrically when I bake.

I come from the other side of the ocean and grew up with the metrics. Switching to cups and saucers was a bit painful, but having done it, now I do not mind it anymore. It actually even looks more logical to cook that way, but not to bake or make fine pastries. Pastries require precision, and there no one can beat good old milligrams.

No difference to me at all. Where I get riled up is when people get overly precise in making conversions. To me, when a recipe asks for 1 pound, I think 500 grams, not 453.592.

I prefer metric because it's a lot easier to scale things up or down. I also convert some of my baking recipes into "baker's percentage" and metric is the only way to do it, unless you are a math genius. And metric is also more accurate at smaller measurements.

Yes to what you say in your head comment. In the past gram weight scales were expensive clunky and mostly for drug dealer.

Now with cheap electronic scales finding their way into the kitchen the landscape is changing.
They're especially useful for baking as flours have different 'cup weight' measurements. An all purpose flour cup in the South (like Martha White, or Gold Medal) will weight differently from a AP flour of the same brand in a Northern Supper market.
I failed at making "no kneed" bread many time before I used a scale for Gold Medal AP flour..With Gold Medal weighing in as 130g/cup and USDA AP flour at 125g/cup. The scoop sweep method for Gold medal flour comes in a bit shy of 130g/cup resulting a wet dough.
http://www.recipesource.com/misc/hints/flour-weights01.html

For flours it's very seasonal and regional for the weight of brand vs a 'cup' of flour. It adds up.

Thank you for your answers. Guess we would have to say it all depends on what you are used to.

I prefer grams for small measurements and especially for baking. I feel its much more accurate. My scale measures both as mentioned by another answer. I wish we converted years ago when we should have...

For the past few weeks I've been testing recipes for a friend's book. I've been following her instructions to the letter and weighing ingredients as variable as green pepper; like maybe using three quarters of a green pepper because it weighs the 4 ounces that the recipe calls for. Neither she nor I actually cook like that in real life, but I've learned from writing recipes that the people who read them can be very literal minded. And I have to offer back advice to my friend on how well the test went.
Where precise measurements matter is in baking. Most kitchen scales you can buy today toggle back forth between grams and ounces; ditto for kitchen thermometers.

Most scales today provide metric and US weights, so it really doesn't matter which system you use, as long as you are consistent within a recipe. The benefit of being adept at both measurement systems means that you can use European or US recipes very easily. I much prefer measuring the weight of an ingredient over messing with cups, etc. I converted most of my recipes years ago and have been happy with the results.

Interesting question. I measure coffee in grams but the rest of my recipes are recorded in pounds, ounces and teaspoons.

Habit mostly, plus it's easier to use the same system from store to storage to mixing bowl (if the recipe calls for 350 grams, how many pounds do I buy?) Grams are more accurate for small quantities, teaspoons are faster where you don't require the accuracy.

It depends. I use the scale a great deal in both cooking and baking. What's most important is consistency. Never switch from metric to U.S. weights within a single recipe, and you'll be fine either way.