I think I'm most proud of playing
Touhou. Embodiment of Scarlet Devil, Perfect Cherry Blossom, and Imperishable Night especially. I don't consider myself a "Lunatic difficulty" level player, but in an instance where I play a new entry and can beat Hard 1cc in a couple tries I don't get surprised. Here's
a video of me beating the "Extra" stage on EOSD with no deaths and no "miss" (meaning you can't get hit and also against boss cards you can't use bombs or timeout). So it is basically perfect except I think one survival bomb. I have pretty excellent Extra clears for PCB and Imperishable Night. On Lunatic, I have a few sloppy 1ccs for Imperishable Night, and a few 2ccs for EOSD and PCB.
F-Zero GX: full completion, including all staff ghosts.
Beating all the built in challenges for
Mirror's Edge 1+2. It's not super difficult, but it is very satisfying (especially ME1).
Perfect Dark: I'm not sure how proud I am of simply 100%'ing the game (e.g., beating Perfect Agent, unlocking all cheats, all simulator challenges, etc) but I can bang it out very easily. I've done it (not easily, mind you) using keyboard-only controls on an emulator where I had to map the analog stick to one set of arrow keys and I mapped "partially titled" analog stick to another set of arrow keys.
Metal Slug 3: 3cc
Doom 1/2: just beating random individual levels on Nightmare difficulty from a pistol start. I challenged myself to beat all of John Romero's levels this way, but "Tenements" (
this level) was too hard. There's two spots early in the level where you have to get through a GAGGLE of spectres (my most hated enemy...grrr!). His other levels are pretty good for this challenge from what I remember, although I doubt I even attempted the late game levels. My favorite memory from Nightmare/pistol start might be map21: Passage to Exile (
this level) from the wad D2TWID.
Dark Souls: they way I challenge myself with these games is that I replay them with full enemy clears, getting all the stupid item pickups (i.e., including the dangerous platforming ones), minimizing repeat trips for each bonfire, no cheesy tactics, limiting estus, and restricting weapon upgrades. On the last point I prefer the combat in Dark Souls where I don't let myself grow in power any more than needed to keep pace against standard enemies. Each character also has some kind of quirky role playing angle too, which limits their shields, equipment and allowed tactics. In Dark Souls 1 I've gotten a 7 death run with these restrictions and in Dark Souls 2 I've gotten a 30 death run. I'm proud that all my deaths against Lud and Zallen were in my first playthrough and now I have a 3 time "win streak" going of consecutive playthroughs where I defeat them (solo) on my first try.