Target's Champion brand last forever and my most recently purchased ones have a key pocket at the back. I bought a new pair because they're cooler looking than the ones I already own, but the other ones just don't die.

These have a pocket where you want it:

Why on earth anyone would put a pocket on the side I can't imagine.

Zibbets -- I actually prefer the side pockets for trail running and hiking, since I usually have a backpack or a hip pack on, which makes a back pocket inaccessible. Arguably, with a pack on, I don't need the pockets at all, but I always find a use for them -- usually the car key, so I don't have to fish for it in my pack, and sometimes my phone if I plan on taking a lot of photos. (I'm wearing a pair of Athleta tights right now, with two zip pockets on the sides and two on the bum, like "real" pants, and I have to say I really like the functionality for my purposes.)

ETA Find.

That makes sense, La P. I don't carry anything but a key, so I'm not concerned with accessibility until I get back to the car/house.

Side pockets are probably great for someone who is not built like me. Honestly, I'd use them if I had slim legs and narrow hips!

Thanks a million for all the excellent suggestions. I'll have some shopping to do next week. The sliding-down pants are waiting to go in the donation bag, and that slims down my workout capsule considerably.

My fave workout /running tights are from Costco. They are like iron. You would have to check on the pocket - mine are quite old and the models have changed. I have also had great luck with ON.
I do have a spi belt for money etc but totally get that you dont want an additional item to carry.

I like Nike, under armour and Athleta. Probably Nike fit me the best and they have lasted the distance too!!

I like MPG athletic pants. I'm pear shaped and find their pants have a high enough waist that won't slip down my hips, a wide enough waistband that doesn't create muffin top and thick enough fabric to smooth out the jiggly bits.

Have you tried the Lululemon in black or dark patterns? I find the pocket placement actually masks my saddlebags, rather than drawing attention to them.