[AkibaSilver]

Kurona's hit the general fan consensus on the head - Dalek is universally loved, and for good reason.

If you're after more a show of action and spectacle than a Dalek character piece, "The Stolen Earth / Joruney's End" is probably the next one to go for, but that one occurs as a series finale, so it also has a lot of returning stuff which is great if you've watched the four previous series, but less so otherwise.

In the last decade, I'm a fan of Resolution, last year's special which does a similar thing of Dalek, what with focusing on a single unit, but also works to be a character piece for one of the current companions. It's not as universally loved as the two above, but I really like it. Plus, I don't want to purely recommend stuff from just one era!

As for all the stuff inbetween, umm... Day of the Doctor has Daleks! And that's cool! (It's definitely not a Dalek episode, but when it's up against Asylum, I'll take it)