What do you know, another meaningless comparison. And again, another close call, which seems to be a theme of mine. I've owned both grills and I currently own a Panini Grill, which may make this a bit biased. In terms of the foreman grill, the consumer is basically paying a bit more money for the Foreman name. The grill I had was quite basic, no temperature control or on/off button, just plug in and grill. I will say that it grilled nicely for an indoor grill.
Cuisinart GR-1 Griddler Panini and Sandwich Press
The panini grill I have is the same basic looking grill, except there's an on/off knob as well as temperature control. The biggest plus is the price is probably 20% lower than a foreman grill (of that size) and does the same basic thing; it grills indoors.
I like to do whats called "spatchcocking" on the panini grill. Spatchcocking is when you take a whole chicken or cornish game hen and cut the back-bone out. This in turn allows you to open the bird like a book and flatten it out on the grill. This works great with game hens that are about 1.5 lbs. on the panini grill. Since the Grill, grills with both sides it cooks a spatchcocked game hen in 10 mins. flat. Delicious. The foreman grill and panini grill do the same thing. If you want to spend the couple extra bucks for a brand name foreman grill, go for it. If not, stick with a basic panini grill.