Michael Ryder, of the Montreal Canadiens, who scored 25 goals as a rookie in the NHL and 30 goals last year, played a full year in the ECHL after finishing his junior career. He's a good example of someone who has turned himself into a legitimate top 6 NHL forward after starting his career in the ECHL. He was drafted in the 6th round by Montreal in 1996. He also played two full seasons in the AHL before graduating to the NHL.
While he hasn't played an NHL game yet, 21-year-old Hamilton Bulldogs goalie Jaroslav Halak started last year in the ECHL before moving up to the AHL near the end of last season. He is now leading the AHL in save percentage, goals against, and shut-outs. Whether or not he develops a career in the NHL or not is still up for debate, but he's doing too well in the AHL for him not to at least get a look. He's a future watch graduate of the ECHL. He was drafted in the 9th round by Montreal in 2003.
Couple errors, Ryder never played a full season in the ECHL and it was parts of two seasons. He started his pro career in Quebec with the Citadelles, but he got sent down to get a couple games in, he played 5 games with Tallahassee of the ECHL. The next year he was back in Quebec but again wasn't getting ice time, so he got sent down early in the season. He played 20 games in the ECHL for the Sea Wolves, made the ECHL All Star's but never played in the game due to a callup to Quebec and he never was back in the ECHL again. He caught fire with Craig Darby and Jason Ward if I recall. So he played in a total of 25 games in the ECHL.
The next year he again struggled to get ice time in Hamilton, as they were stacked (that's the best AHL I ever saw live, not that I see a ton of AHL teams live though) It was Claude Julien that asked GM Andre Savard to keep him in Hamilton instead of going back to the ECHL. Ryder didn't get much ice time early on but he often scored when he did play, so he made it impossible to sit him. What a year he went on to have, was really good in the playoffs along with Jason Ward.
Ryder was also drafted in the 8th round, not the 6th, he went 216th overall.
As for other players for the Habs, Halak should see the NHL at some point, he's got 8 SO's in the AHL in his first 26 starts. Francois Beauchemin played 7 games in the ECHL with the Sea Wolves during his first year as a pro. Gordie Dwyer played 36 games in the ECHL, 108 in the NHL, but that's the only Hab drafted players I can think of that saw any time in the ECHL and NHL.