The new Doom is on the cusp of getting its first major update, and it appears to be worth checking out -- especially if you have fond memories of the original games. The upgrade arrives on June 30th with the option of a classic dead-center weapon view, regardless of the mode you're playing. It's there to evoke nostalgia, of course, but it'll also be helpful if you want more of a visual aid when aiming.
Other additions? Aside from the usual fixes, there's a photo mode to capture those brutal battles for posterity, and the SnapMap creator has useful extras like sky backdrops and an auto-rollback feature to mend corrupted maps. This is just the start of Doom's expansion plans (more maps and game modes are on the way), but hey, it's free -- there's no harm to checking it out.