All releases of the theatrical versions have their drawbacks. Presuming, you want widescreen, you have three main options.

GOUT upconversion- These are upconverted versions of the DVDs released in 2006, normally with restored theatrical audio. They have better clarity than laserdisc-sourced projects but have DVNR motion smearing. The best of these is Dark_Jedi's V3. Available on myspleen.
Theatrical Reconstruction- These are reconstructions of the theatrical version by combining the 2004 Master and the GOUT using a great many sources (from film cells to upconverted versions of the GOUT) in order to create a reconstruction, with the overall quality of an HD version of the 2004 version. They often have a lot of effort pit into them in order to restore things. The average viewer may like these the best, but the most minor of changes may still exist in these and they have crushed blacks (like the 2004). The best is Harmy's HD Despecialized Editions. Available on myspleen or megaupload (links on tehparadox).
Non-DVNR'ed Laserdisc Transfer- This is the option Asaki mentions. They are transfers of laserdiscs, with none or less DVNR then compared with the GOUT, hence less motion smearing. The picture is usually softer and fewer preservations of these have been made. Arnie.d.'s V8 is the ideal choice for ANH, sourced from a Japanese NTSC laserdisc; Asaki kindly uploaded it to Demonoid. As for ESB and ROTJ, you'll probably want to go from something from the PAL laserdiscs; I would suggest Moth3r's PAL laserdisc transfers (which can easily be converted to NTSC with a program like DGPulldown and luckily still found on tehparadox).