I tried both Roku and a HD antennae. Of the two I decided I would rather use the antennae. The Roku irritated me to distraction. That was about three months ago, so maybe something has changed for the better. At least with the antennae there is no monthly fee, but the downside is that there are only about ten channels I can get - and half of the time I can’t get more than one. (Trees and in a valley) A better antennae would likely help out a lot. I preferred it because it was simple as changing channels in the same way I am used to doing with cable.
SO, what we ended up doing is downgrading our cable package to the ‘starter’ line-up and keeping our internet service (no one else to get that from here). Saved $80.00 per month!!!
I still have one TV set up with the antennae in case the cable has an outage.
If the antenna doesn't have a signal booster, get an in-line booster to put between the TV and the antenna. Also, antenna placement can make a difference. Looks like Best Buy has several under $50. If your antenna has a built in booster make sure it is plugged into a power outlet and turned all the way up. (I just noticed one of the rabbit ear antennas with a booster at Best Buy was cheaper than most of the boosters). Sorry for the lack of a clickable link; cut and paste should work:
http://www.bestbuy.com/site/searchpage.jsp?id=pcat17071&st=antenna+amplifier
add XTV on your ROKU - its free and great - thats all I ever have on anymore