I am a translator and work with GBs of text, in many different formats, which I would like to be able to search. I have tried every desktop search program under the sun, and always end up coming back to these three: dtSearch, Copernic and X1 Search. In my latest tests, X1 Search seems to be winning. My ideal tool should be able to do many things, but here are a few of the most important ones: (1) index tons of files (at least 500 GB), (2) ability to preview files of up to a GB or so (i.e. big files) without choking, (3) not slow down my computer, (4) actually find everything (duh). dtSearch is very powerful, but its UI leaves a lot to be desired. Copernic is pretty good, and has improved a LOT lately (looks like they are throwing money at it at the moment), but I think X1 is currently the best.