Definitely Remember Tomorrow... I guess Opeth could have made a slightly more original version of the song... but its still a great performance. Really hoping to hear more covers in the future, done in a more Opeth-ish style.
I'm so glad I bought the limited version when it was more widely available... I've seen it go for quite a bit on ebay (but then a lot of people on ebay are stupid and pay stupid prices for things). It was the first Opeth CD I bought, but now that I am a big fan I'm glad I had that foresight...