<strong><span class="infobox-head">TONIGHT </span></strong><br /> <strong>&ldquo;Three Rivers&rdquo; </strong>(8 p.m., KCTV) is CBS&rsquo; latest attempt at a medical drama, and wouldn&rsquo;t you know, it has a little &ldquo;CSI&rdquo; in it. (Not necessarily a good thing &mdash; &ldquo;CSI&rdquo; ratings are way down.) But this one takes place at a fancy organ-transplant unit. &ldquo;Moonlight&rdquo; star Alex O&rsquo;Loughlin plays a doc who&rsquo;s part of the team that turns tragedy into triumph as organ donors&rsquo; remains are compassionately harvested and used to give others new life. CBS has been tinkering with this show all summer, and it still needs work. Alfre Woodard and &ldquo;L Word&rdquo; alumna Katherine Moennig co-star.</p><p><strong><span class="infobox-head">MONDAY </span></strong><br /> In <strong>&ldquo;Sherri&rdquo; </strong>(6 p.m., Lifetime), &ldquo;The View&rdquo; panelist Sherri Shepherd plays a struggling actress on a talk show &hellip; just kidding! In her sitcom world she picks up bit roles, makes money as a paralegal, is a single mom dealing with the recent betrayal of her ex (Malcolm-Jamal Warner) and has a domineering dad (James Avery). Clearly the people writing this show have been watching a lot of Tyler Perry; there are elements in &ldquo;Sherri&rdquo; you wouldn&rsquo;t have seen in a sitcom five years ago.</p><p><strong>&ldquo;Imus in the Morning&rdquo;</strong> (5 a.m., Fox Business Channel) emerges from the relative obscurity of RFD-TV and signs on at its new home, just across the street from MSNBC, which fired the I-Man in 2007. See my story in Monday&rsquo;s FYI.</p><p><strong><span class="infobox-head">WEDNESDAY </span></strong><br /> <strong>&ldquo;Mythbusters&rdquo;</strong> (8 p.m., Discovery) returns for a new slate of bang-up episodes, and this week&rsquo;s puts the emphasis on bang. Adam Savage and Jamie Hyneman are going to test the theory that a bullet dropped by the human hand falls at precisely the same rate as a bullet fired from a gun. The simple secret of this show is that just getting there is four-fifths of the fun, as Adam and Jamie will prove by setting up ever more violent devices to launch the projectile as they work their way up to the real deal.</p><p><strong><span class="infobox-head">SATURDAY </span></strong><br /> I&rsquo;ve been meaning to tell you about the latest Saturday-night film option: &ldquo;Reel Impact,&rdquo; on the Planet Green channel, offers some of the edgier enviro-themed documentaries. Many have played at the biggest film fests, like <strong>&ldquo;Grizzly Man&rdquo;</strong> (7 p.m.), the story of grizzly bear advocate Timothy Treadwell, who spent 13 summers and an estimated 35,000 hours among the Alaska grizzly before one of them turned on him. This controversial film from director Werner Herzog will look even better on Planet Green&rsquo;s HD channel.</p><p><hr class="infobox-hr-separator" /> <div class="infobox"> <strong><span class="infobox-head">TONIGHT </span></strong><br /> <strong><span class="infobox-head">MONDAY </span></strong><br /> <strong><span class="infobox-head">WEDNESDAY </span></strong><br /> <strong><span class="infobox-head">SATURDAY </span></strong><br /> </div>