It's PES/ISS, tbh. I'm fine with Contra, okay with Castlevania, never loved Metal Gear at all, not into Silent Hill, but was a huge DDR fan for awhile and think of it fondly.
My love of Konami is mostly because of their licensed stuff in the '90s: TMNT is probably my favorite Konami "franchise," though of course, it's not one really. I just think of it that way, even today, because to me, they did the definitive TMNT games. Tournament Fighters, Turtles in Time/Hyperstone Heist, etc.
Then you have the X-Men arcade game, The Adventures of Batman and Robin SNES, etc. Their licensed game juju was STRONG.
If I'm picking my favorite game based on a Konami original IP, it's Sunset Riders, so yeah...
My favorite Konami original IP games:
1. Sunset Riders
2. DDR 5th Mix
3. PES 18
4. Gradius
5. Konami Pixel Puzzle Collection (I can't express how much I love this game, second-best mobile game ever, trust me on this)