If you need voice-acting, then you're less likely to get the best out of the freeware scene. Because these games are made on a zero budget, voice-acting is a rarity.
The white chamber has voice-acting and is a sci-fi horror story.
The Silver Lining is a fan-made sequel to the King's Quest series with full voice-work. There is still one episode yet to be released and it's a single over-arching story so it may be worth waiting for that to come out.
The Ben Jordan series didn't start with voices, but voiced editions have now been created for all episodes to date. The long awaited final episode is due shortly. Unlike The Silver Lining, the individual episodes are largely stand-alone adventures anyway, though there are recurring characters. The exception is probably episode 7, that ended on quite a cliff-hanger.
As for a top 100 list, such a task is far easier said than done. Keeping up for the monthly articles is a major job as it is.