Posted: 29/05/2013 at 13:30
Hardtropicals (http://www.hardytropicals.co.uk/forum/) is the place to get more inspiration.
Verdun's suggestions are spot on though for Palms, the only one provan truly hardy in the UK is Trachycarpus fortunei. Canary Island Date Palm (CIPD) is not hardy and should be seen as annual bedding apart from fortunate places in coastal Cornwall etc. Otherwise inside a dry greenhouse all winter, but they grow big.
Musa and ensete look the part and canna musifolia are tropical looking and give the jungle look.
Salina's suggestion for Euphorbia is also spot on!
Rodgersia, Ligularia, Rheum, Gunnera Manicata, Bamboo also immediately come to mind.