I'm working with RAW formats for my pictures and i need something that can do about the same as Photoshop lightroom and if i read correctly what's on the web for that, Gimp is not the best solution.
Why don't you start by getting your requirements down and in order? There is no program that is called "Photoshop lightroom" so people might find it hard to imagine a proper replacement for a non-existing piece of software. Also we don't know what exactly did you read on the web that indicated Gimp might not be the best solution - best solution for what?
If however you were looking for replacements for Adobe Photoshop or
Adobe Lightroom or
the combination of both programs:Photoshop:
I consider Gimp + UFRaw to be the full equivalent of Photoshop/ACR (with the possible exception of 16-bit depth) and in many cases far superior to Photoshop because of its flexible plugin/addon structure and its CLI capabilities which allow Gimp to be scripted.Lightroom
DigiKam is the equivalent to Lightroom in as far as cataloging, rating, (geo)tagging, sorting, organising etc. etc. your images. The Kipi-plugins give it direct links into any major image-hosting site as well as added (batch) editing capabilities.Photoshop + Lightroom
If you use Digikam for organizing and 16-bit image-wide edits (Rotation, perspective, shear, levels, curves, vibrance, whitebalance, noise-reduction, sharpening) and Gimp for pixel-level 8-bit edits (cloning, liquid rescale, resynthesis based content-aware fill etc.), you have the best of both worlds and something that can easily stand the comparison with any other image suite out there, on any OS, full stop.
Note: Tex has been so kind to add Gimp Paint Studio (GPS) to the repos when I pointed it out. It greatly enhances the capabilities of Gimp with a multitude of presets, brushes, backgrounds, patterns etc.
A second must-have is the GMIC plugin for GimpAll programs described above are available through Synaptic with the exception of Photoshop and Lightroom.