I love towers and yagi's, but like wire antennas with gain a whole lot more. They are more stealth, easier to maintain, and much cheaper to put up. Not to mention a fun challenge to do right.
For 80M I put up a wire based short hatted vertical dipole - with a hefty center wound set of coils, and it took two winter DX seasons to get DXCC on that band. No gain - omnidirectional - but a lot easier to earn that I ever expected.
For 40M I used a 4 element Bruce Array - up about 13 feet on the bottom - fed as a vertical dipole on one of the center elements. 4.2 db gain with 20 db FB. A real barn burner antenna - and MUCH better than any variation of dipole that I tried. Main reason was height - I have never been able to get a 40M dipole or EDZ up the required 1/2 wl minimum - where it would have made a real diffence. Low hanging dipoles are very limited.
For 30M I used an aluminum short hatted vertical dipole - but it easily could have been made out of wire.
For 20M and above, I have had the MA5B, C3SS and SteppIR 2 element yagis. All fine antennas, but I have proven that these wire antennas work just as well at a fraction of the cost:
Moxon
Bruce Array
K1WA Array
Quad - 2 element
Now - if you can put up a large boom yagi or LPDA - 3 or more full sized elements, you will do very well. Funny thing about yagi's at my location - they get swamped with noise due to large power lines on a hill way above my QTH.
I was able to A-B compare my SteppIR 2 element yagi on a Force-12 LPT-1242 40' crank up - and my 4 element bruce - and even K1WA array consistently beat it - and it was all about S/N ratio. Both the wire and the yagi seemed to have the same signal strength - and no wonder their gain was about the same - but the wire antennas were quieter. This means that those rare DX stations that were buried in the "frying pan noise" on the yagi were quite intelligable on the wire antennas.
So - when I hear the old wives tale that "if you want to DX, you need a tower and yagi - don't bother with wire" - I laugh.
Now - if I only had the space that they did in Palos Verde - to put up a whole bunch of rhombics - then we would be talking.
Also - the best wire antennas that I have tried all seemed to have some connection with Bell Labs in NJ - or with space radio astronomy.
I earned 8BDXCC between July 2001 and July 2004 - almost all with wire antennas and 200 watts or less. I know - this is all anecdotal - but I did always use EZNec and a decent antenna analyzer to make sure that I was building the antennas correctly. I even cut phasing lines properly - and everything I built was documented in the ARRL Antenna Book or the ON4UN Low Band DX book.
What wire antennas (with gain) do you swear by for DX-ing?