I think that these three episodes are great and a brilliant way to start the series.
Partners in Crime: This is a very good first episode to start the series with. Donna Noble (Catherine Tate) is searching for the Doctor in this episode, they cross paths quite often and will eventually find each other. Donna works for Adipose Industries which is a company which have come up with a drug which will make you lose weight. Little do the people know that the fat in you will become little creature called Adipose, which will then absorb your body. The owner of the company has a sonic pen which she occasionally uses against the doctor. This is a very funny and exciting episode with a alien, which for once is non-threatening which makes a change. There are lots of laughs with Donna and the Doctor and Rose unexpectedly turns up..... A great way to start the series. 9/10
Fires of Pompeii:
This is definetley my favourite episode of the three episodes. The Doctor takes Donna for her first to Ancient Rome, or so they think; they actually are in Pompeii and they're there the day before volcano day. The Doctor and Donna look round getting to know people, little do they know that they are being followed by some people called the Sisterhood. Fire Creatures turn up from the volcanoes causing very dramatic scenes. In the end the Doctor has too make the sacrifise of killing all 20,000 people. This is my favourite episode of the three because it is very high-paced, exciting and 'explosive'!! 10/10
Planet of the Ood:
On the Ood are re-introduced after appearing in Series 2. This time the Ood aren't in control of the devil, they have a disease called Red Eye. The Doctor very early one realises there is a third source, that something else is there in control of them, that thing is the huge Ood Brain. This has a very entertaining feel to it and is very exciting. There is a very gruesome yet cool scene where a man pulls the skin off his head and tentacles comes out his mouth and he becomes an Ood. This is a very good episode.
In conclusion this is a great buy and I seriously reccommend that you purchase this, after all they are 3 outstanding opening episodes to the series. Overall: 10/10