There are several tropical and exotic-looking plants that can be grown successfully in the UK, despite the cooler climate. Here is a list of hardy tropical plants that can add an exotic touch to your garden:

1. Trachycarpus fortunei (Windmill Palm or Chusan Palm)
2. Musa basjoo (Japanese Fiber Banana)
3. Fatsia japonica (Japanese Aralia or Paper Plant)
4. Cordyline australis (Cabbage Palm or Torbay Palm)
5. Phormium tenax (New Zealand Flax)
6. Dicksonia antarctica (Soft Tree Fern)
7. Eucalyptus gunnii (Cider Gum)
8. Chamaerops humilis (Mediterranean Fan Palm)
9. Canna (Indian Shot)
10. Tetrapanax papyrifer (Rice Paper Plant)
11. Colocasia esculenta (Elephant Ear)
12. Gunnera manicata (Giant Rhubarb)
13. Yucca gloriosa (Spanish Dagger)
14. Hesperaloe parviflora (Red Yucca)
15. Ophiopogon planiscapus 'Nigrescens' (Black Mondo Grass)
16. Schefflera taiwaniana (Taiwanese Umbrella Plant)
17. Trachelospermum jasminoides (Star Jasmine)
18. Passiflora caerulea (Blue Passionflower)
19. Aloe striatula (Hardy Aloe)
20. Agave americana (Century Plant)

Please note that while these plants are generally considered hardy in the UK, individual results may vary depending on microclimates, planting location, and care. Some plants may require winter protection or be grown in pots to be moved indoors or to a greenhouse during colder months. Always check the specific requirements for each plant to ensure it will thrive in your particular garden.