Well I have
A pair of girls aged 4
A pair of boys aged 8ish months
A lone boar...but hopefully not for much longer... ;-)
I had only ever had girls having been fed the usual 'two boys will fight' line by pet shops (we weren't aware of rescues back then!) until earlier this year my blokey and I popped into P@H (sorry) for some supplies, and there was this little boy on his own at the back in the adoption centre...next morning Dodge came home...
I do agree with what people say that boars are often more cuddly than girls. As for more personality, I disagree - I think it's just different personality. My girls definitely know their own minds and have their own little ways, but you need to know them more to see them. It's like when Whiskey was ill, most people were like 'well she's eating and drinking, she's fine' but she just wasn't 'her'. Boys on the other hand are a bit more in your face with their little ways, I find.
Boys I have found to be a bit easier to bond with humans - Dodge was quite afraid for quite a while but I think this is due to his start in life, now he is a proper chatterbox and can really look after himself. My other two boys have been here a week now and already have the hang of when dinner is, JoJo is already getting good at nearly falling out the cage to get closer to the food I am preparing! My girls are a bit more aloof, however vocally Whiskey is THE loudest guinea I have ever had, she can literally wake me up at night.
I think really the only answer is to do what I have done and get loads of guinea pigs, hehehe!
Oh yes, best add, my lot live in the pairs mentioned above - 2 girls together, 2 little boys together, and Dodge and, erm, well, watch this space...let's just say he is making it known he misses other guineas.