Depends upon what sort of flying and how much you want to spend.
But, I'd look at the Thruster T600, X'Air (the original not the later "Falcon" model), and Chevvron 2-32c for starters. If you want ultra-cheap look at the Thruster TST or Cyclone AX3 which are selling for around £4-£5k for a reasonable 2-seater these days, or if a bit more money to play with a Sky Ranger or Eurostar.
If you aren't in a hurry however, the microlight show at Popham on the May bank holiday weekend would be a worthwhile trip - you'll see a huge range, chat to their pilots, and no doubt if you take your chequebook that there will be some spirited attempts to sell you a few which you can use to grab a few free trips and see what you think.
G