Best deals with 02 in the UK???

Well, welcome to O2 lol. Basically, with your monthly top-up you get a free monthly allowance (a tariff). And if you want, you can pay out of your credit for an extra calls/texts package (a bolt-on). You also get O2 Treats (option of free calls/texts) if you've been with O2 for more than 3 or 6 months (can't remember which one). And you get O2 Rewards every 3 months (10% of all your top-ups back every 3 months). Check out the links below to see which tariff/bolt-on would suit you: