All you should need to run these statements is a mysql prompt or phpmyadmin access. Cut/Paste the query in and see who's using/abusing your site.
Without further adieu:
Most Stories:
select count(sid) as c_sid, aid from stories group by aid order by c_sid desc limit 10;
Most/Longest Stories:
select sum(length(bodytext) + length(introtext)) as length, aid from stories group by aid order by length desc limit 10;
Most Comments:
select count(c.sid) as c_sid, u.nickname from comments c, users u where u.uid=c.uid group by c.uid order by c_sid desc limit 10;
Most/Longest comments:
select sum(length(c.comment)) as length, u.nickname from comments c, users u where u.uid=c.uid group by c.uid order by length desc limit 10;
Read the most stories:
select count(v.sid) as c_sid, u.nickname from viewed_stories v, users u where v.uid=u.uid group by v.uid order by c_sid desc limit 10;
Read most comments:
select sum(v.lastseen) as s_seen, u.nickname from viewed_stories v, users u where v.uid=u.uid group by v.uid order by s_seen desc limit 10;
Busiest comment raters:
select count(cr.sid) as c_sid, u.nickname from commentratings cr, users u where cr.uid=u.uid group by cr.uid order by c_sid desc limit 10;
"Grumpiest" raters:
select count(cr.sid) as c_sid, cr.rating, u.nickname from commentratings cr, users u where cr.uid=u.uid and cr.rating=1 group by cr.uid, cr.rating order by c_sid desc, rating asc limit 10;
"Happiest" comment raters:
select count(cr.sid) as c_sid, cr.rating, u.nickname from commentratings cr, users u where cr.uid=u.uid and cr.rating=5 group by cr.uid, cr.rating order by c_sid desc, rating asc limit 10;
Best Rated:
select avg(c.points) as avg_rating, u.nickname from comments c, users u where c.uid=u.uid group by c.uid order by avg_rating desc limit 10;
Busiest Voters:
select count(p.qid) as c_votes, u.nickname from pollvoters p, users u where p.uid=u.uid group by p.uid order by c_votes desc limit 10;
Most popular poll options:
select aid as poll_item, avg(votes) as avg_votes from pollanswers group by aid order by poll_item limit 10;