The Doctor's Wife- If I was to look at episodes which suffered the most from budgetary limitations, this would definitely be an example I would point to. Neil Gaiman's concepts are so imaginative and so crazy that they would never be realised on a BBC budget.
The dialogue is golden in this story, as are the performances from the leads. Although the focus is on Smith and Jones (see what I did there? ), Gillan and Darvill get some excellent scenes, and the plot regarding them isn't dull at all. The main plot focuses on The Doctor and Idris, and it's brilliant. Suranne Jones gives a brilliant performances, and she really is believable as being the physical manifestation of the TARDIS's soul (well, the TARDIS's matrix, but that doesn't quite roll of the tongue as simply ).
I've always thought that the title was odd. The TARDIS isn't the Doctor's wife, so I don't have a clue why the episode is called that if I'm honest.
The main problem is the supporting characters. There is a very small cast in this story, and they all do a fine job, but the characters of Auntie, Uncle and Nephew are really bland in my opinion. House is great, but the others aren't interesting at all. This is an example of where the budget ruins a good idea. Auntie and Uncle are supposed to be made of body parts stolen from other creatures, but their appearance really doesn't give off that impression. Also, why is Nephew an Ood? The inclusion of an Ood always felt forced to me, as it adds absolutely nothing to the story, except for allowing a few references to previous stories to be made. The makeshift TARDIS console doesn't look that good either. Gaiman has this same problem in Nightmare In Silver, his concepts are often ruined in their execution.
Overall- 8/10.
This high score is well earned by the excellent performances and Gaiman's wonderful writing. The pacing is good, as are most of the visuals. Just about everything in this episode is great except for the couple of issues I mentioned previously.