I don't have a lot of Four stories left - half of the Invasion of Time, a few from the last season, and just one last story after this remaining from Sarah Jane's first run on the show. Fannish consensus is fairly heavily against The Android Invasion, but I think this is a bit unfair, perhaps driven by the fact that it is not a particularly glorious farewell to Harry, Benton and UNIT as we first knew it. I thought the creepiness of the village which is not really a village, the general concept of the android doppelgangers, and the sinister Kraals behind the scenes, worked rather well. Admittedly the Kraals' plot makes No Sense At All, but they are neither the first nor the last baddies in Who of whom this is true. Also we get to see Tom Baker playing the Doctor's evil double (as again with another story reviewed below).
The Stones of Blood was one that I remembered fondly from first time round, and I liked it again on re-watching three decades later. Perhaps, now that puberty is behind me rather than yet to come, I appreciate Mary Tamm's costumes as Romana all the more. But of course I also have a fascination with megaliths, and this is the only broadcast story that really uses them (though see also the SJA story The Thirteenth Stone). And of the three stories featuring an ancient cult in England within a few years of 1980, this is the only one that really pulls it off well (the other two being Image of the Fendahl and K9 and Company).
I either missed most of Meglos first time round or else just wasn"t concentrating. It too is rather excoriated by fans, but it reminded me rather of the middle-grade Pertwee stories: there is one absolutely wooden performance, Edward Underdown as Zastor, and the special effects are dire (watch Tom Baker's legs disappear as he walks across the desert, and also we have plant monsters almost as bad as in The Chase). But there is plenty to like: the Grugger/Brotadac relationship, the return of Jacqueline Hill as Lexa, the whole concept of an evil cactus, and, again, Tom Baker playing the Doctor's evil double and getting a lot more to work with this time. It isn't the best story of the season by any means (that is probably Warriors' Gate), but it's not Tom Baker's worst either.