The WRT54G (and GS) are good specifically because there's a variety of third-party firmware out there for them that add tons of features not found in other consumer-level devices, and that also means those devices will be maintained (bug fixed etc.) for a long time after Linksys stops caring about them. Their wireless range is okay but not excellent, and their hardware reliability is good in my experience.
I've heard bad things about the DI-524; the DI-624 seems to be a better choice. The DI-604 wired routers I have used seem okay, basic but they work.
I don't know anything specifically about the Netgear WGR614, but all of my recent experiences are that Netgear sucks now. They were once a good company, but now they're doing everything too cheap - poor designs and Indian tech support who doesn't know anything about their products you can't find in the manual.