Post WW2 America has dragged us into far more conflict than we should have been part of. I think the only conflict the UK has entered of it's own accord is the Falklands war. Other than that it's been UN peacekeeping forces, NATO operations, or (and these are the problem ones) trying to make US operations not look unilateral (e.g. Iraq 1 & 2).

They've also made sure all our innovation goes to them first.

Now I'm sure there have been benefits to having the US in our corner, but I think we've been exploited in a lot of ways for the sake of the "special relationship".

If the Brits had never lost the US, it would now be a similar country to the other anglosphere countries i.e. much more stable and normal with a parliamentary system. Wouldn't necessarily not have a president - there are former colonies with Presidents but they still work with a parliamentary system. The States could still have their own governments and have their own rules, and a federal government too (like Australia). You could still celebrate an independence day - when you severed ties from being British subjects (like in Australia - also same day the first fleet arrived in Botony Bay and set up the internment camp so it's "invasion day" to the First Nations folk understandably) or when you signed a treaty with the indigenous folks (NZ) or when you decided to become a confederation of states (Canada). Honestly it would've been great to have kept the US in the British Empire for longer as you'd have kept the British sense of humour.