Two great summerslams!

Summerslam 1998
This is a pretty solid PPV, the matches involved all have good stories behind them and are enjoyable to watch.
The Hair vs Hair match is great, fast paced action and even though a common jeff jarret guitar ending, it was still pretty good, although, when they shave the losers head, they don't do a very good job!
The No holds bar match is short but eventful, spike piledriver on a chair! The story leading into this is interesting and this match is the third best of the night.
The ladder match, even though slow at times, is still one of the best one on one ladder matches i have seen, even though that looking back now, the spots in the match aren't that stand-out or unique, it is still a great match and probably the best on the card.
The WWF title match is the average affair, not as good as the ladder match, but it is still very good, undertaker hits a leg drop from the top turnbuckle to the annouce table and the match is memorable, and finishes off a great PPV.
Other matches such as the Lions Den match and the European title match are pretty good and may not be as good as the ones i wrote about in detail, but are worth watching as they are still pretty entertaining., it was also nice seeing edge make an appearance.

Summerslam 99
This is just slightly better than the 1998 PPV.
The european and IC title match is great, the ending is pretty surprising and is the perfect PPV opener, fast, interesting and very well done.
The tag team turmoil match shows the great skills of the tag divison here, as the tag divison would only get better from here, Edges' spear from the railing is rather epic and i had to watch several times, it was awesome!
The Hardcore championship match was good, seeing Road Dogg running around with Snow and boss man was cool, but i thought the match went on for a bit too long, seeing them go outside the arena like they did was great, but got boring fast.
The "love her or leave her" street fight was great, lots of action, great match, lots of highlights that will make you want to watch the match several more times, some of the spots you would see shane mcmahon do several times in the future, so this is one of the best matches of the night.
The Kiss my ass match was alright, as was the tag team match, not the best matches of the night, but still both worth watching, the kiss my ass match is rather funny at times.
The triple threat match is great, three great men in the match with Jesse Ventura as the guest ref gives us a great match, not filled with many spots, it still was great though, the best match of the night, but the crowd seemed to be somewhat dead after the match was over, the segment after the match i though was rather unnecessary, but in the months following, it would make sense.

Overall, the PPVs here are great and feature some great matches, as i said Summerslam 1999 is just slighty better than Summerslam 1998, but both of these PPVs are worth the purchase, go buy it!

Two great Pay Per Views with memorable moments.

Summerslam 1998

Best Matches:

Triple H vs. The Rock IC Title Ladder Match - 10/10

Stone Cold Steve Austin vs. The Undertaker - 9/10

Mankind & Kane vs. The New Age Outlaws - 8/10

Three match event but these matches are worth the buy alone.

Summerslam 1999

Best Matches:

Stone Cold Steve Austin vs. Triple H vs. Mankind - 8/10

The Rock vs. Mr.Ass - 8/10

Shane McMahon vs. Test - 8/10

Tag Turmoil match - 8/10

Great event all the way through better than 98 as an event with less memorable matches.

Overall great events both very entertaining and one of the best tagged classics you will find.

a great tagged classics release! 2 awesome summerslams.
summerslam 98 has the great ladder match between triple h and the rock, not forgetting another brilliant encounter between the deadman and the rattlesnake. the leg drop from the demon of death valley is an all time iconic undertaker moment imo.

summerslam 99 follows the fantastic tradition of great summer wrestling events with some great matches and storylines going on at this time: the hardcore match, rock vs mr ass and triple threat main event are the stronger of them.