Benchmade makes great knives and are one of the leaders in the industry. Without knowing your particular uses and preferences, the no-brainer suggestion would be a Griptillian.
You can get a standard Griptillian for right around $100 and a Mini Griptillian for a little less than that. Personally, I tend to prefer the Mini because my "sweet spot" for blade size is right around 3". The Griptillian in either size is an iconic knife for EDC; you can't go wrong with it as a choice. It also features one of the best assets for a knife; the Axis Lock. I have several different Grips and they're one of my all time favorite EDC choices.
If you're concerned about weight, you might consider the Benchmade Bugout. I personally don't own one but I have a feeling someday I will. The Bugout will push your $100 target budget by a few dollars however.
There's also the Benchmade Freek, but I've never quite understood it's place in the world. Anything it can do, the Griptillian seems to do a little better...but that could be a matter of opinion.
Finally, take some time watching the Exchange here at Blade Forums. You might luck into a gently used Benchmade 940/943 or another model that would normally be out of your price range. You might even find an "upgraded" Grip for not much more than a new vanilla one. I've bought several knives here and the members are great to deal with.
Good luck and welcome to Blade Forums!