Very much a B-movie, Wishmaster has a lot to offer fans of horror.
The story is a fun one, as we don't get too many Djinn-focused horror flicks. What made it even better, though, was the solid cast. Tammy Lauren did pretty damn well as the main star, despite not really being in all that much of note (the only place I know her from is the 1988 television remake I Saw What You Did, co-starring Shawnee Smith).
Most everyone else was a pleasure too. We had some Kane Hodder, Tony Todd (fantastic as Johnny Valentine), Robert Englund in multiple scenes, some narration by Angus Scrimm, and a fun character played by Jenny O'Hara, who, I kid you not, I only know from a random episode of House (the series starring Hugh Laurie). This movie just had a fun bunch of actors and actresses, and even the individuals who I didn't care for as much (such as Andrew Divoff, who was a bit too hammy at times) did okay.
Also, the special effects need to be brought up. A few times, they didn't work out well, especially when they went the hideous early CGI route, but overall, the special effects through the film were something to behold (at both the sequence at the beginning and the party at the end, it's endless eye candy, such as the great skeleton scene and the half-alligator man). So many of the death scenes were well-done (great jaw-ripping scene), and the special effects just looked great.
Wishmaster is no doubt a B-movie, but I think that works out in it's favor. I really liked Lauren's acting, and her character's final wish was pretty clever. While I cannot speak on the necessities of the sequels (I've seen only the second Wishmaster, and was deeply displeased), I can say that this one is very much a movie worth checking out. Having seen it twice, now, perhaps three times, I think you'll have a fun time.