Jim’s v. Grandpa’s: Which Burger Haven Is the Best?

Denver is home to a lot of great burgers in varying styles, but there are really only two contenders in the old-school smashburger category, and that’s a tale of two Burger Havens.

Long before Whataburger returned to Colorado in 2022, it operated several locations in the state back in the late ’50s. When that brand pulled out of Colorado, the location at 595 East 88th Avenue in Thornton went independent, when Jim and Arlene Moser founded Jim’s Burger Haven there in 1961.

Over the years, Jim’s expanded; a second location still operates today in Westminster — but by 1980, the only Denver location, at 23 South Federal Boulevard, had split off to become Grandpa’s Burger Haven. Last year, fans panicked as news broke about new owners at Grandpa’s, but the stand remains mostly the same today, with a few minor improvements.

The similar names often cause confusion, which is exacerbated by the fact that the two spots also have very similar menus, including the same signature item: large, smashburger-style patties served on a massive 6-inch bun. The two burgers have more in common, too, but only one reigns supreme.

The Burger Showdown

We recently visited Grandpa’s and the original Jim’s in Thornton on the same day to make a fair comparison. At both, we ordered the large size (on a 6-inch bun) double cheeseburgers as they come — a single here just won’t do, as the patties are very, very thin. The standard toppings at both are the same: lettuce, tomato, onion, pickle and mustard.

Here’s the lowdown on the differences:

Grandpa’s Burger Haven

The place: A small, bare-bones shack on Federal Boulevard where you order at the counter and eat outside or in your car.
The price: $9.49
The burger: The slightly squishy bun is lightly buttered and toasted, which adds to the perfectly greasy experience. The patties are nicely charred, and there is an ideal toppings-to-patty-to-bun ratio. Plus, we could really taste the melted cheese.
The rest: Grandpa’s has replaced its former letter-board menus with a more upscale display. Prices have risen by a couple of bucks for the burger since 2019, but others have dropped, like cost of the corn dog, which is down from $2.54 to $1.79. Grandpa’s has also expanded its offerings under its new owners, with additions such as shakes and floats, chicken wings and mac-and-cheese nuggets.

Jim’s Burger Haven

The place: A retro diner with counter ordering and plenty of comfy booths and tables inside, where music from the ’50s and ’60s plays in a dining room that gets lively during the rush.
The price: $7.55
The burger: The bun here was toasted but not buttered, and it was much denser; that contributed to an overall drier burger experience. The pickles were superior — Jim’s uses a thick, ridged dilly chip (similar to the ones used on the pickle pizza at the PZA), while Grandpa’s pickle was a thin, darker-hued, standard sandwich pickle. The patty here lacked the char that we found at Grandpa’s, though, and the toppings, especially the lettuce, were skimpier at Jim’s.
The rest: As a much larger restaurant, Jim’s offers a wider selection beyond burgers than does Grandpa’s, including local Polidori Italian sausage, a fried cod sandwich and an Iowa pork loin sandwich.

The Winner

Jim’s has some advantages for sure, from the dining room to the extra menu options, and its signature item sports a cheaper price. But flavorwise, even its superior pickle couldn’t save it. Grandpa’s is the clear Burger Haven champion based solely on burger flavor.

Even after eating more than enough burger bites than we were hungry for, we reached for Grandpa’s burger again. It’s the one that elicited a “yum” after every bite — whereas with Jim’s, our response was more “ummmm?”

But we still think both are worth a visit. Because does it really get any better than affordable eats from a legacy business with plenty of nostalgia and a good milkshake to boot?