TT Volume 5 (like most people!) - I thought it was OK & did the job for me.
IMC confuser - essential
For both, check out Amazon before going to a pilot shop - usually a fair bit cheaper.
Also, not essential but useful, got from ebay for -I think - £35 the OAT IMC DVD, it was much better than I though it'd be having not used OAT material before.
From the same seller I scored the Night Qualfn DVD too for under £15 even though I've already done it. Again, was also very good & useful for brushing up.
Definately check out ebay for the DVD's as they can be well under half retail price but be warned, each one usually is being chased by several people so keep an eye on it.