Well, POTF2 Jabba was pretty accurate to the 1997 Special Edition Jabba he was supposed to depict. Not Hasbro's fault that he looked dissimilar to ROTJ Jabba.
Compared to "standard Jabba" from ROTJ, TPM, and the revamped 2004 DVD ANH, the Episode I "Jabba Glob" actually has a really good sculpt; Hasbro even repainted it and rereleased it in the Ultra line as ROTJ Jabba (sans the goo).