I just finished "The Silent Stars Go By" and was less than enthused. Some bits are really good, particularly the Doctor/Amy/Rory banter at the beginning. But the ending feels kind of rushed and there's a lot of just running around being chased by things.
"The Wheel of Ice" is excellent. But then, I'm biased because I'm a huge 2nd Doctor/Jamie/Zoe fan. In particular, I think the book finds some interesting new facets to Jamie & Zoe's characters. Jamie suddenly finds himself in a position of responsibility when he becomes the unwilling de-facto babysitter for a bunch of rebellious teenagers. Meanwhile, the normally cold & logical Zoe finds her softer, more emotional side when she's stranded alone with a small child and needs to comfort her. (There's a great callback to "The Mind Robber" here.)
"Dark Horizons" was pretty good. For another great story of the Doctor alone on primitive, pre-Renaissance Earth, check out the 10th Doctor saving a medieval village in "The Krillitane Storm."
"Prisoner of the Daleks" makes the Daleks dark & scary in a way that the new TV series hasn't really managed. (The simple act of enslaving humans for pointless manual labor does a better job of conveying the Daleks' cruelty than a million exterminations ever could.)
"Judgment of the Judoon" isn't a great story but it's got a quirky combination of characters. The Judoon commander gets a great deal of character development. And I can't believe how long it took me to realize that the Nikki Jupiter character is totally a Veronica Mars
I enjoyed "Ten Little Aliens" more for the gimmicks, like the choose-your-own-adventure section, than for the story itself. But it does a pretty good job of getting into Polly's head and exploring some aspects of her background as a modern swingin' '60s girl. (Aspects that they couldn't really get into on a 1960s children's TV show.)
I highly recommend anything written by Terrance Dicks. "World Game" & "Players" are 2 very good companion pieces featuring the 2nd & 6th Doctors, respectively. Dicks simply knows how to craft a compelling, easy to read sentence. And he has an immediate grasp of all the characters. Perhaps it's not surprising that writing for the 2nd Doctor comes as second nature to him. But I was very pleased with how astutely he captured the sarcastic banter between the 6th Doctor & Peri.
It's been a while since I've read them but I was very fond of "Wolfsbane" with the 4th Doctor, Sarah Jane, & Harry and "Loving the Alien" with the 7th Doctor & Ace.
If you like your Doctor Who
on the weirder side, you might try "Mad Dogs & Englishmen" and "The Coming of the Terraphiles."
Of the recent 11th Doctor/Amy/Rory releases I've read, I really loved "Borrowed Time" & "Dead of Winter." Both of them seem to actually take some time to try to give us a better sense of who Amy & Rory are and what's going on in their heads.
"Nuclear Time" is probably the most uneven of the books that I've read. The concept of the Doctor traveling backwards in time is an interesting one. And there's some interesting emotions going on with some of the guest stars. But the author clearly doesn't know the first thing about writing for Amy or Rory. (Also, strangely, the author sometimes describes certain things about the 11th Doctor's wardrobe that are just wrong. There are several references to the Doctor wearing boots. And even one bit where he's described as wearing jeans!
"Festival of Death" is a 4th Doctor/2nd Romana story that feels perfectly at home amidst the TV stories of Season 17. It's got everything: Time paradoxes. Romana making snide remarks about the Doctor's TARDIS driving skills. K-9 running around saving the day all the time. And a suicidal computer that feels like it's straight out of the mind of Douglas Adams himself.