I recommend the Express at Holiday Inn at Buckhurst Hill. There's a Watford's supermarket at the trainstop (I think Loughton), but then it's a 1km walk UPHILL!
2 hour train ride from LHR.
Why do I recommend it? Oh man.....they have a toilet ensuite! I stayed there when they first opened. Unknown now if they have changed the sheets since then.
Spock Seat :-: