<p>There’s not clear cut answer, it’s a tradeoff. CS61C is not horribly difficult but can be quite time consuming because of lots of projects/assignments/etc.</p>
<ul>
<li>My choice to push back would be EE20. I found EE20N to be useless anyway. However, it’s easier than 170 or 188.</li>
<li>188: The knowledge of 188 won’t really help you in any other upper div classes. However, it’s a relatively easy class to get an A in (because of the curve and Cogsci majors taking it, no offense) so it may a good fit with 61C. And it’s interesting (if you’re into AI).</li>
<li>CS170: Can be pretty time consuming as well, depending how good your math/proof skills are. On the other hand, I wouldn’t push it back because its knowledge will really help you with your future CS classes.</li>
</ul>
<p>61C + 170 + 188 is doable, but can be a though schedule. CS170 is one the the classes that’s very easy for some but hell for others, it depends. In terms of future usefulness I’d say that this schedule is #1. </p>
<p>61C + 188 + 20N: Easiest schedule out of those, but you’ll lose the benefit that 170 gives you for later CS classes.</p>
<p>61C + 170 + 20N: At least you’ll get your lower divs out of the way 
In terms of time/easiness it’s somewhere in the middle.</p>