You know... that bit with stealing Yahtzee's hat and the Feed Dump phrase made me realize I have a question. Are you guys going to be at the Escapist Expo? You aren't listed on the info as far as I can see. It's just something that popped into my head so I figured I'd ask.
Other then that, I honestly don't care for any of the time machines. The phone box looks bland and has the time passing issue. The hot tub just is too silly for me. The primer is needlessly confusing. The delorian (spelled it wrong, I know) is can cause problems depending where you go. And, while I like Doctor Who, the 'science' used to explain the TARDIS is either entirely theorectical or just made up. I don't care for made-up science since most anything can be explained by someone good at bullshitting. Plus, the TARDIS just seems a bit too... I'm not sure how to describe it. Deus Ex Machina-ish maybe? It just seems like it basically gets to do, or not do, whatever the writers need it to do/not do whenever they need it to.
Out of all of them, I'd likely choose the TARDIS in all honesty. But I'm not a huge fan of any of them. Though it doesn't help I haven't seen 3/5 of the movies/shows the devices belong to anyways.