Something similar to Mahler

Thanks for all the input. I'm a Big Orchestra fan. Honestly, I do have complete list of Mahler symphonies. Also Bruckner and Shostakovich. Shos is another favorite, however I wouldn't compare to Mahler since I found the 2 composers are very different from each other.
Bruckner is pretty close, especially symphony 4, however Mahler is more emotion and less "attack" compare to Bruckner.
The reason I picked 3 and 5 cause I found them most sensible and beautiful pieces from Mahler. Of cours other are wonderful too, like the 4,8 or 9, but they are on a different scale.
Smetana is great and of course "ma vlast" is always the most beautiful song for me. I'm not familiar with Karoly Goldmark, but will give it a try.
Alexander Nevsky is pretty powerful as well. R.Strauss, Holst (the planets) are very "attack" and "fire"...
Again, what is most closest to Mahler 3 or 5? Especially 5?
:)

It has to be said. No one is like Mahler! His sound/music is unique. The closest I can think of would be Hans Rott in his Symphony in E (Hyperion). Listen to this and you might think he is composing in Mahler's style, actually he preceeded him a tad.

That aside, if someone hasn't already mentioned it, listen to some Janacek (Simphonietta and Tarus Bulba), Suk (Asreal Symphony, Ripening, and Praga, as well as Serenade for Strings), and Lizst's Faust Symphony.

By the way you don't mention Mahler's 6th Symphony. Have you heard it? If not, do so - its manditory Mahler!

Try Schoenberg's Verklarte Nacht. You'll be pleasantly surprised how beautiful and romantic this piece is.

Liszt Faust Symphony. Very good idea. Hear the version of Ivan Fischer, BFZ, Philips.

Something close to Mahler, which is not really Mahler, is the so-called Mahler 10th symphony (in the performing version by Deryck Cooke), since Mahler skethed much of the music but died before it could be completed and orchestrated. Admittedly, this music is much closer to the Mahler 9th symphony than to the 3rd or 5th, but still an intruiging work, that is rarely heard.

Try the version by RSO Berlin, Riccardo Chailly conducting:
Decca 466 955-2.