Cell seems to have a fairly good rep, though I personally can't say first hand.
ODIN, I'm assuming you're looking at
eBay? Well, from what I can see, many issues with that. 1, no service guarantee. 2, it's being put together at best by a production liner, at worst by an untrained hireling who may be following some manual, if you're really lucky, 3, no test riding first. Stay well clear.
Repco, well, it used to be a good brand, but all the new ones are cheap K-Mart bikes, which again means no service guarantees, put together by a kmart worker who probably has no idea about bikes, and no test ride.
Just because it has Shimano stuff, even good Shimano stuff, on it, doesn't make it a good bike. Shimano make componentry from really good top end gear, to bottom-of-barrel-scrapings you'll find on el-cheapo bikes. And any manufacturer can buy the componentry and slap it onto their bike, doesn't mean the bike itself is any good.
If you're at all serious about cycling, and are stuck to that budget, then I would definitely not buy new. For that price, you'll only get a crapola bike that you won't ride. Instead trawl the bike shops and perhaps
ebay for good second hand bikes. Then once you get used to the ride, and perhaps can afford a bit more, get yourself a new bike from a good shop. That way you'll know what you like/don't like/want in a bike.