I personally know probably around 150 people and I wonder if I have to name them all when I pray for the conversion of sinners. There will always be some people outside your household who mean something to you and you wish would convert, but if i name only my parents and siblings, i feel i neglect those others, and if i name only my parents, sibling and those other certain ones, i feel i neglect the rest, so then i feel like i should name them all so as to not leave anyone out, but then this becomes a little bothersome to do each day, so then i get back to thinking if simply saying "for the conversion of sinners" would be enough and sufficient.

Would God and Our Lady really not convert someone you know simply because you didn't name the person in your prayers? Would naming the person or not really make a difference and decide whether the person will end up converting or not?

I strive to say 3 rosaries a day.  Not that I do, I try.

First Joyful mysteries rosary:  For all clergy, living and dead and religious/seminarians.

2nd Sorrowful:  For all those in need of conversion/those in agony, purgatory

3rd Joyful: For all our family members living and dead and friends.

that is an idea.

Malleus - If all of these 150 people you mention really mean something to you, it may be meritorious for you find a way to pray for them all personally.  If that means you have to pray for 10 per day and cycle through them over a 15 day period, then that could work(although there may be another better way to cycle).  Another idea would be to do all 150 on sundays or fridays, and the rest of the week do efficient and fewer more all encompassing prayers.  

I would sometimes split my intentions over morning and evening prayers when my intentions would grow in numbers.  Because, all of these things that I pray for really mean something to me.  However, for me, it works best for me to keep my intercessions limited and combine where I can.  Matto's advice works.  I do that with certain prayers/times, and I wouldn't think of doing it any other way.  But, it varies.  It all depends on how much you have to give/sacrifice.  

Mt 18: 12-13 might be useful to read.  Christ rejoices over the one lost/found sheep than the ninety-nine that hadn't gone astray.  So, again, if you are moved by each of the 150, consider it from that angle.  They all are worth it.

God knows who you are praying for whether you name them of not. Please pray for me.

One night I was training someone from another property. As part of the training I had to leave this person alone. I decided to pray the rosary and offer it up for someone who was dying. It was around 1:30am. After I got off work that morning I went to another church for the daily mass. I was expecting to go to a day of reflection but that was scheduled for another day and I was mistaken. Before mass started the priest came out and said, "I have an announcement. A parishoner of ours just died last night at 1:30am."

God knows those to whom we intend to send our prayers.  I simply add, after a relatively-short list of specific names, "and for all those for whom I generally intend to pray, for all those to whom I have offered my prayers, for all of my benefactors and friends, for all those whom I have hurt by my sins and for those who have sinned against me."  I do this in the context of having offered all of my merits and prayers in general to Our Lady according to the philosophy of St. Louis de Montfort.  I trust her to distribute the merits of my prayers as God would desire that they be distributed.  Otherwise, one can be overwhelmed with scrupulosity and even neurosis.  Plus there's the angst of trying to figure out how much to distribute to each person.  This way we put the entire values of our merits, such as they are, in Our Lady's hands, to distribute accordingly.  Our Blessed Mother will handle everything perfectly for us.

Of course, we don't really have any merits that aren't communicated to us from Our Lord anyway.  It's like a parent who gives his kids a little allowance money, and then they save the allowance money to buy some gift for their parents.  That money comes from the parents in the first place, and the parents have far more than what the kids give back, but it's all about the heart and the intent.

So one of the many secondary benefits of consecration to Our Lady is that we offload this particular worry and concern from our hearts.  I ask her to distribute the merits of these prayers as SHE desires.  Otherwise I can get carried away with wondering whether I should pray more for souls in Purgatory or for the conversion of sinners or for whatever else.  Our Lady knows best.