I played a game called Gear Head a while ago. I don't remember much about it, but I remember liking the concept a lot. You were a mecha pilot guy and after stocking up on space suits, space rations, guns, boomerangs, knives, etc you would get in your mecha thing and fly off to space stations and asteroids and planets, and dismount and go through these "dungeons".
I remember hating the extremely complex controls, especially in regards to piloting the mechas. But I enjoyed the idea of guns, aliens, randomly generated missions, piloting vehicles, etc. What other modern or sci fi roguelikes are out there? Preferably ones that really pull it off well, not just act like Angband but the swords are renamed "light sabers", the plate mail is renamed "powered armor", and the crossbows are renamed "blasters".