Whilst on my trip to London last week I visited a great bar right near Oxford Street, i've probably stared right at the building before without a clue there is a viewing deck inside with waiter service and amazing cocktails! If you live in Manchester I suppose it's the Beetham Tower (Hilton) equivalent.
It was handy being able to pre book, as me and @KT_Millar had just been to a trend seminar down the road at the Fashion Retail Academy; we simply gave our name at the door, they put us in the lift and next minute we were in the bar with the most fantastic view of London. We were lucky enough to catch the sun setting, which really was a fantastic view from where we were sat.
Paramount bar, inside the sky scraper building Centre Point is well worth a visit if your in central London.
See the website: