Pants.

whole loaves.

cheese

Beer

Unsliced bread or, in its absence, cake.

indoor plumbing

Sex, and sliced bread supplanted it by a landslide.

I must note that Sliced Bread was first sold in 1928 (not as long ago as I thought, although Wikipedia said the first prototype bread slicer was made in 1912, HAPPY 100TH BIRTHDAY SLICED BUT NOT AVAILABLE TO THE PUBLIC BREAD!). So the automobile, telephone, light bulb, phonograph, camera (still and motion), steam locomotive, morphine (first of the opiates), aspirin (first of the non-opiates) and comic strips all predate the Wonder Bread.

My further inventionarial research showed that the modern design of the bicycle (called a 'safety bicycle') was introduced in the 1890s, although it took a few years to replace the pre-existing 'pennyfarthing' style and banish the design to Patrick McGoohan's fevered imagination. And the derailleur gear system was developed in FroglandFrance in the 19-oughts. But further Wikipedic cyclesurfing show the first gasoline-powered motorcycle with two same-sized wheels came out in 1885 (Google "Daimler Reitwagen") and steam-powered cycles go back to the 1860s.

And did you know that the modern version of the Pizza (at least the 'Pizza Margherita' with cheese), was first made in 1889? (For Queen Margharita of Italy, using the colors of the Italian flag, tomato red, basil green and mozzarella white) And Cheese goes back so far into pre-history, nobody's sure who first thought of intentionally spoiling milk for fun and nummyness.

But for a nummy food that clearly predates sliced bread, the Wikipediatricians claim that the first recipes for Pie Shells go back to First Century Rome, and who's gonna deny THE PIE?

On this day of the Stupor Bowl, I also had to look up the first air-filled ball for playing games, apparently also from Roman Empire times, the 'Follis' or 'Balloon Ball'. As a kid who was frequently hit by all kinds of sports balls (NO GENETALIA JOKES, you know what I mean), I always preferred the inflatables. So, Inflatable Balls? Hell, yeah.

And then there are Punch Cards, which were what I first learned computer programming with (yes, I'm THAT OLD, but also my college computer lab was TOO CHEAP for individual terminals), which predate computers by over two centuries where they were used to run the Jacquard Loom, which is one of the coolest examples of OLD technology I know, then evolved into the Player Piano Roll. (The RIAA tried to outlaw home paper punches because they encouraged music piracy)

As for the other things already suggested...
Pants? Who says that was a step forward?
Beer? Like cheese, going way back and you can't figure out HOW it got invented, but as soon as somebody realized that alcohol was getting made, I'm sure it got a lot of R&D support...
Sex? Well, it couldn't have been 'invented', although it is said that face-to-face sex is one of the first things that set us aside from other animals and the first couple who tried it HAD to be either totally fearless or WAY kinky.

Among all that (I AM being longwinded today), I'll declare that my favorite invention BEFORE sliced bread has to be...
THE THERMOMETER (invented in 1709 by Daniel Gabriel Fahrenheit, naturally), which allows me to obsess about the weather AND my own health.

Dammit I have to stop showing up in threads right after oneswellfoop.

Air conditioning. Yes, it dates from before sliced bread.

I'm gonna say friction or "Lucifer" matches.

Before them, in order to start a fire you needed to carry flint, steel and tinder or get a chunk of fire from someone else's fireplace.

After them, you could strike the little stick anywhere and bring forth an immediate flame.

The sewing machine. And, arguably, the zipper and electricity.

Dammit I have to stop showing up in threads right before Glinn

Buttons.

Fire. The wheel. The Firewheel.

Actually whole loves, IMNSHO, is still better than pre-sliced bread. A sharp bread knife and a cutting board is great. And the bread doesn't dry out. Assuming of course that it's a real loaf of bread and not the styrofoam that passes for bread these days. My lawn, remove yourself from it.

And Cheese goes back so far into pre-history, nobody's sure who first thought of intentionally spoiling milk for fun and nummyness.

I always wondered how people figured out stuff like that. "Right, and if we add some animal rennet, it will be even better!"

And how did they figure out how to scramble eggs? Ok, I can see the egg falling out of the chicken and then breaking, and ... then what? How did they know to add milk and butter?

And ...

I've always wondered about wine. You make wine and it's all cloudy with dead yeast but it becomes nice and clear with the addition of a little extract from fish flotation bladders. Who figured that out?

I think the cheese thing came about from using animal organs to store liquids and food. You store it in a tied-off bladder, nothing much beneficial probably happens, but oh, Ihkran put his in a stomach, and it's chunky now, and the chunks kind of taste good...