Via Real across from the Four Seasons is excellent - southwestern food and very good margaritas. (There are also all the various things at the Four Seasons like Cafe on the Green.)

Cool River is a steakhouse concept also on MacArthur (between the Four Seasons and 114) and they have fairly good food (the menu keeps changing but the game dishes used to be excellent when I lived by there and dined there two or three times a week) - the bar scene there can sometimes overwhelm the restaurant but that may be your scene! As a solo diner, I often ate in the cigar bar).

A couple of other choices that are a bit further afield - Pappas Bros Steakhouse on Northwest Highway is one of the best in Dallas. (At that same juncture there are a half-dozen other psuedo-chains like Humperdinks, Pappadeaux, Pappasitos, etc.)

If you like good sushi, Jinbeh on Las Colinas Blvd is good... and I also love Thai Chili a few doors down.

Depending on where you are staying in Irving, I'd recommend possibly getting a bit out of the Irving city limits. I live immediately north of there so if you'd like other suggestions, feel free to PM me today and I'll be glad to send you a few more (let me know what you like and what your scene is!).