Okay, i decide to make this topic!
Let everyone just post his + and - for each software he played(at least couple of times).
My list:
Netent - my favorite software.
+ Best looking games in the world
+ A lot of really different games with different features
+ High winning potential in many games
No minuses.
Microgaming - played quite a lot in past, but recently tired of this software.
+ Home of awesome 243 lines games(IR, TS II, Playboy, etc).
+ Some good old games.
- Generally many clones of each others, just copy old game in new one, i do not like it.
- 243 liners can eat money forever.
Playtech - few years ago was my favorite software.
+ Wide range of different games with interesting features.
+ Many games with tight base game, but with a lot of retriggers during feature.
+ Marvel slots(wonderful marvel slots).
- New games by playtech...Not interesting at all.
- Some games has ability to suck money even better than MG 243 liners.
Nextgen/Nyx - like this games.
+ Interesting and good looking games.
+ New games has intereseting and new features you don't see at other softwares.
- Old games are very similar to each other.
Real time gaming - played a lot with no deposit bonuses.
+ Super turbo play!
+ Frequent hits of features.
- Many slots pay bad in features(at average).
- Old games(most of it).