Well.. By not picking the obvious. I'm gonna go with Perfect Strangers, that one has really grown on me over time, and the version on this EP is one of the better versions. I also like The Big Medley because I love the the first 3 or 4 songs, it's the last ones that I'm not as big a fan of so it kind drags this one down after a strong start, still great covers.
For what it's worth, I think the worst part has to be the Led Zeppelin Medley. See, I'm not that familiar with Led Zeppelin as it is, but I know enough of them to appreciate their significance and relevance to rock music. Now, I've always though DT are great at covers, sometimes taking the music above and beyond the originals in some cases. But I'm not feelin' the Led Zeppelin cover. Something's a bit off in these ones, I dunno if anyone else feels this way about them.