The PPL Confuser is good. Apparently the only book that uses questions from actual old exam papers.
Don't take the time limit seriously though. For example, the Met section has 120 questions which you are expected to finish in an hour. In the actual exam there are only 20 in the same time period - you typically have more than enough time - I have so far written Air Law, Navigation as Meteorology and this was true of all of these.
To qualify my comments about the Oxford CD-ROMS. I have only seen the Air Law one - I believe the Met one was done in conjunction witht the Met Office. The test questions were quite good but some seemed to be off-sylabus. Again - I don't think the Air Law is well done - think 1960's school TV - I bought it for the visuals but in fact there is no animation and there is better visual material in the books. It's very slow going - you can read much faster and there's no summary to go back to - you have to make your own notes.