I know it's a vague question, and I know the right answer is "the best RB I can get." But realistically, who are the RBs you like that are getting drafted in the RB3 range (ie, roughly RB20-RB30 on draftboards)?
Based on the cafe's PPR rankings, I probably like Addai the most with Pierre and Larry Johnson not too far behind. I'd be more than satisified to have any one of these 3 as a RB3. Hell, I could probably live with one of them as my RB2 if I paired up a top-tier RB with a couple top-tier wideouts. Addai I actually have in my top 15 RBs and Pierre and Larry Johnson both are in my top 20.
There's a few guys I would target based on the Cafe rankings.
20-30 Range (in order I like them relative to value) DMac - I'm finding myself out more and more on a limb here but I really think DMac has a chance to surprise this year. There's not much "proof" I can give outside of a gut feeling about it though. I just think that a healthy McFadden, without the turf toe injuries, can produce and even on the Raiders. The reports are that he has been doing everything right to return from last years injury riddled season. You also have the reports about the Wildcat in Oakland and DMac is the RB for that game plan. The drawbacks, which I've taken into account, are Oakland as a team and MBush. Of course there's something that tells me that Oakland in general just doesn't have faith in MBush even though he could very well be the better back. But even if Oakland goes with a pseudo RBBC with MBush doing the between the tackle work and DMac doing the stretch type plays, passing downs, and Wildcat; I'm still higher on DMac then where he is currently being drafted.
LJ - Everyone is discounting the one RB in this grouping that has a legitimate shot at finishing as a top 10 RB. It may be a long shot, but if it happened there wouldn't be too many that were overly surprised. Most would look back and say that they could've seen it coming. Combine this with the fact that KC wasn't nearly as bad running the ball last year as many seem to think and the lack of a passing game (the loss of Gonzo will hurt and Cassell isn't in NE anymore) is going to help LJ as he will be the primary weapon and get plenty of dump off passes.
30-40 Range McGahee - Plain and simple, this is the single most under valued RB in my opinion this year. Last year Baltimore's backfield was a mess and yes everyone is back this year. But Willis was hit with injury after injury and appears to be healthier this year and I think he can stay that way unlike last year. Many will point to McClain but he is a FB that happened to play RB last year but he will be moved back to the FB role for the most part. Others will point to RRice, but he just didn't impress me last year in the chances he was given. At worst, I see a competition during preseason and Willis will distance himself as the main RB in Baltimore leading into this year. As the start of the season draws closer, Willis will consistently move up the ADP rankings week by week.
Personally, if I could land a solid 1RB and 2 of these 3 guys to platoon as my 2RB, I wouldn't be concerned and I think it's a valid strategy to employ as you may be able to land a RB in the 1st round, WRs in the 2nd and 3rd rounds, and then 2 of these guys in the 4th round and beyond.