I started this following a discussion with a few others and we came to no conclusion (not that there is a 'right' or 'wrong'), but the question as per the title of the thread: When do you arrive at the gate (when travelling alone)?

A common answer in the discussion was just before boarding starts (supposedly), but personally boarding never starts when at the 'boarding' time at LHR so I usually aim for a couple of mins before gate close. At T5, the gate agents seem to never care/boarding is still in full swing but I flew AA out of T3 the other day and the gate agent was in some sort of limbo panic.