If you are looking at engineering or Science then Imperial, Kings College and Manchester are certainly good, but Imperial, and Kings College have international reputation.
But if you are trying for UK , then apart from Imperial, and Kings try for UCL, Oxford and Cambridge.
I say the best universities in UK (Science & Engineering) in descending order are
1.Oxford and Cambridge (You can never go wrong
)
2.Imperial
3.Kings
4.UCL
5.Manchester
Economics, Business and Commerce in descending order are
1. London Schools of economics & London Business School (You can never go wrong
)
2. Oxford
3. Cambridge
4. Imperial
5. Warwick/ Manchester