The whole strip vs. fremont street argument isn't really one worth having after you think about it for a while: yes, the Strip has the forum & the wynn & thomas keller & mario batali & all the expensive clubs, but have you BEEN to Bill's Gambling Saloon? Imperial Palace? Excalibur? Have you had a yard long margarita while browsing Nanette Lepore's boutique? Let's not forget where we are, people.
That being said.. the Nugget is probably the only place I would ever stay downtown. And I'm not just saying that because my friend allows me to crash here with her for free (okay, maybe). Rooms are totally clean and decent (not as dingy looking as excalibur), they have wi-fi in the rooms, wonderful frozen drinks by the pool (try the pina colada!), plenty of nickel slots and you can get decent fried rice and steamed vegetables delivered to your room. I also enjoy the Belgian Waffle Utopia, mostly because it's fun to say.
(Yes, I have been to Vegas all of two times and have spent considerable time in 4 different hotels. What of it!?)