Gogarth E1s and E2s are brilliant. From my experience so far:
The Strand is a good introduction. Purely to annoy certain people, I'll say again that it's like climbing 2 strenuous HVSs in a one-er. Being single pitch, not 'by the sea', and with abseil decent, it's not really Gogarth.
North West Passage is absolutely superb. The position and climbing on the second pitch is second to none.
Toiler on the Sea is excellent. My first route at Gogarth, and a suitable gripper (especially as my mate decided the best way in would be to ab on the climbing ropes).
Resolution Direct I found a bit disappointing. Run the final pitches together to avoid belaying in the middle of the best climbing.
Atlantis/True Moments/Freebird is probably the best one I've done. Like North West Passage but loads better (unbelievably!).
Worth bearing in mind that pitches at the far end of Main Cliff (e.g. Nightride, which has an excellent pitch) are a whole world of faff. The approach faff is really enjoyable, the exit faff less so. Easter Island Gully (Hombre is very good) is a similar deal. If you like a few pitches of steep grass to top off a good route, head round there.
I can't resist the temptation of saying that if you climb E1/2 then The Moon is the best route available. Sorry about that.
Aardvark is a great test, with superb crimpy slab climbing on the cusp of E3.
I haven't done Flytrap yet but that looks amazing. So do Mousetrap and Red Wall for a bit of classic loose fun (none of the routes above are loose) but they're bird band 'til August.
In reply to rustaldo: I don't know, I've not done them all - when I have I'll let you know ;-)
However, everything I have done there has been extremely good. Out of the 4 you mention (which I have done), IMO, Mousetrap knocks the sock of the other three in terms of the all round experience. It is just completely unique and utterly compelling.