If your problem is remembering things
You want capture. Todoist for the best natural-language entry across every platform, or TickTick at $3.99 a month if you want habits and a Pomodoro timer bundled in. Apple Reminders or Google Tasks if free and already-installed wins. All four are good and none will let you down.
If your problem is that the list never gets finished
You don't have a capture problem, and a better list app won't help. You need the day to have a shape: Sunsama (~$20–25/mo) for a guided ritual, Akiflow ($34/mo monthly) to consolidate everything, Motion if you'd rather an algorithm decided, or Fuidzy if you want to drag it yourself for free.
If your problem is that you keep building systems instead of working
Be careful with Notion, ClickUp and Amazing Marvin — all three are excellent and all three reward configuring, which is the exact trap. Pick something with very little to fiddle with.
If you want it free
Obsidian (with work), Loop for habits, the built-ins for lists, or Fuidzy for a full timeline, habits, focus and shared plans at $0.
Capture problem → Todoist or TickTick. Time problem → Fuidzy, Sunsama or Motion. Knowledge problem → Obsidian or Notion. Most people who've tried four apps have a time problem and keep buying capture apps.