We recently replaced our counter tops & installed a new gas range, and lo & behold, we now have discernable gaps on both sides of the stove next to the counter top.

Not finding any solutions I liked online, I remembered the rubber weatherseal I recently used around our doors in our house:

weatherseal-1  weatherseal-2  weatherseal-3

I purchased the above weatherseal at Lowes, but I’m sure any decent home improvement store will have a similar product.  The one shown above is a high performance EPDM rubber D-profile weatherseal.  You could probably use it ‘as is’ in the gap, but I split it down the middle (split shown in 3rd image above) & only used half of the weatherseal in each gap.  I found it in two sizes (1/8″-7/32″ and 3/16″ – 5/16″) and in two colors (white & brown).  Here’s what it looks like installed:

countertop-1  countertop-2

countertop-3  countertop-4

I didn’t remove the self-adhesive strip paper.  I just gently pressed the weatherseal into the gap for a pressure fit, and it hasn’t moved.